The Nook Color is an excellent ebook reader, but it can also be a top-notch Android tablet. Follow our step-by-step instructions, and your Nook will be running Android, in all its glory, in no time.

Barnes & Noble’s is, in the company’s own words, “the reader’s tablet.” It looks like a tablet, it checks your email like a tablet, and it can get you online like a tablet. From a hardware standpoint, the Nook Color stacks up well against other 7-inch tablets, including the and the . But unlike those other tablets, it doesn’t run full Android, which means you don’t get access to the 200,000-plus Android Market apps. For the full benefit of Android, you have to add it to the Nook Color yourself.

We’ll show you three ways to transform your Nook Color to an Android tablet. Two of these methods let you choose whether you want to run different versions of Android or the Nook OS each time you boot; the other leaves most of the Nook customization intact, but adds Android Market access and a few clever Android features on top. None of the three methods is irreversible, none will break your Nook Color (unless you try really hard), and none will take you longer than an hour. They are, however, almost certain to void the device’s warranty, so proceed with caution.

You’ll need three things to get started: a Nook Color, either an N2A card (see below), or a blank microSD card along with a computer or card reader that accepts microSD cards. It’s important that your microSD card be at least a Class 4 card, and preferably Class 6 or higher; two of these methods boot and run the Nook Color from the card itself, so you’ll want a fast card. Also, make sure to get a card with a minimum capacity of 4GB, though 8GB or higher is ideal. You’ll use nearly 4GB just for the Android OS, and you’ll want extra space for your own apps and files.

First up: the simplest way to get Android running on your Nook Color.

N2A Cards

The easiest way to turn your Nook Color into an Android tablet requires no technical knowledge and only about eight seconds of your time.

It involves nothing more than inserting a microSD card from a company called N2A (they’re available in 8GB, 16GB, or 32GB models, respectively priced at $34.99, $49.99, or $89.99) into your Nook Color’s card slot. Every time you power on the device, you’re given the option to boot into either Android or the Nook OS. If you decide you don’t want Android after all, just turn off the Nook Color; take out the N2A card, and you’ll never even notice it was there in the first place.

, so I’ll spare you the gritty details, but in essence: N2A uses a well-known Android ROM called CyanogenMod, which is based on Android 2.3 “Gingerbread.” It’s a solid operating system, adding a variety of apps and features as well as access to the entire Android Market. This version has been customized to run on the Nook Color, but it’s not as tablet-friendly as Android 3.0 “Honeycomb.” (For more, check out our review of the N2A Card.)

N2A cards are certainly the easiest and least-risky solution, but you’re essentially paying a convenience fee—N2A does nothing you can’t do yourself. N2A will even help you do it yourself, if you’d like; the company has detailed instructions on its website.

N2A lets you use either the Nook OS or full-fledged Android. But what if you want the best of both worlds? That’s where nooting comes in.

Nooting

In addition to being a funny-sounding word, “nooting” is a clever solution to the Nook Color/Android tablet problem. It’s rooting (Nook + rooting = nooting), but only slightly; you’re changing some system-level settings, but not performing a complete overhaul. The Nook Color already has long battery life, Web browsing, apps, email, and media support, plus Barnes & Noble put a lot of time and effort into making a nice, simple, reader-friendly skin on top of Android. So why fix what’s not broken?

Nooting mostly leaves the Nook Color as it is, and adds necessary features on top of it. First and foremost: the Android Market. You’ll have access to all 200,000-plus Android apps, and they’ll run just like they would on any other Android tablet. Nooting also adds the Android-standard Home, Menu, and Back buttons, along with a few other enhancements like an Android-style app drawer.

But nooting doesn’t do away with the Nook Color home screen. It turns it into an app, leaving the browser, settings, and menu enhancements alone. Instead of abandoning the Nook environment and diving headfirst into Android land, nooting leaves you with a Nook on steroids.

Nooting is a bit more difficult than adding an N2A card, but it doesn’t take long, and can be done without much technical knowledge—though carefully following the instructions is important. First download the requisite files, which you can find at XDA Developers. Next you’ll need to download an application called ClockworkMod (check the first link of this XDA forum), which lets you manage, recover, and install the operating system, then burn it to a microSD card.

If you’re using a Windows computer, the simplest way to burn ClockwordMod is by using an application called Win32DiskImager. Once you’ve installed it, insert your card and open the program. Select the ClockwordMod file (make sure it ends in “.img”) in the “Image File” menu, then select your card in the “Device” menu. Click “Write,” and wait—it takes a while. (If you’re using a Mac or Linux machine, check NookDevs for easy instructions. Ignore the specific files NookDevs mentions; just go through the steps with the files you’ve downloaded. )

Once you’ve burned the card, add the nooter file you downloaded previously, as a ZIP file, to the card. Then eject the card from your computer and turn off the Nook Color. Pop the burned card into the Nook Color, and install the nooter file by following the instructions here (start underneath the bullet that says “Let’s Get Started,” at instruction #3). The process takes a few minutes, but it’s a simple one.

One thing to note: Unlike with the N2A cards, which let you go back to the standard Nook OS just by removing the card from the slot, your Nook Color will remain nooted forever—unless you reset the device to manually revert it to its factory settings. There are two methods for doing that: the 8 Reboot Method and the Factory Reset Method.

With this method, though, you’ll be working with older, non-tablet-optimized versions of Android. If you want the latest Android OS, here’s what you need to do:

Running Honeycomb

All of the run OS 3.0 “Honeycomb.” It’s the first version of Android optimized for tablets, with everything from the included apps to the menu and notification screens redesigned to look and work better on larger screens. If you want the best tablet software you can get, it’s possible to get it running on your Nook Color without a lot of extra steps, though you will have to make a number of compromises.

The process is the same as with other versions of Android: Download the image file (as always, from XDA developers), burn it to a microSD card using the instructions from above, and insert the card into your powered-down Nook Color. The next time you turn on the Nook, it will automatically boot into Honeycomb. If you want to change back, just turn off the Nook, take out the card, and turn the device back on.

Unfortunately, there’s a problem: Because Google hasn’t open-sourced the Honeycomb code the way it has with other versions of Android, developers have had to cobble together bits of the Software Development Kit, emulator images and previews, and lots of hacking and guesswork. The result is that the version of Honeycomb you get with this method is more proof of concept than it is actually useful Android tablet software—and it doesn’t work particularly well.

Though it can run apps, it doesn’t have access to the Android Market, so you’ll have to sideload any content you want. You can download apps and files from the browser via GetJar or other sites, but it’s more difficult than the Market. There are plenty of bugs, like the accelerometer: Sometimes, when you rotate the device, it guesses your display size incorrectly and extends its image off the screen. Basic functions like the browser work nicely, but this is not an operating system for the average user. It’s also much slower than the other, older versions of Android that can be run on the Nook Color.

When Honeycomb is finally open-sourced, expect a high-quality version of it running on the Nook Color in no time. Until then, you’re better off with the older, more developer-friendly (and thus Nook Color-friendly) Gingerbread.