Tethering's the talk of the town in the smartphone world these days, and Android is no exception. With the introduction of Sprint's mobile hotspot option for its HTC EVO 4G -- not to mention the newly unveiled $20-a-month tethering plan for that other smartphone platform -- there's a lot of confusion over what you can and can't do when it comes to Android and tethering.

Tethering, in case you aren't familiar with the term, is using your Android phone like a wireless modem: You connect your phone to a computer, then harness its 3G or 4G connection to surf the Web on your PC.

That brings us to this week's Android Power reader question, which comes from tether-longing Android fan David W.

David writes:

I've seen you say that you can tether for free on Android. I have the EVO 4G. Don't I have to buy Sprint's $30 hotspot plan in order to do it on my phone?

David's question is one I've been hearing a lot lately. The simple answer is that if you own the EVO 4G and want full mobile hotspot functionality -- that is, being able to connect multiple devices to your phone over Wi-Fi at the same time -- then yes, in most cases, you'll have to pay for Sprint's $30-a-month plan. (There is a way around this, but it's a pretty complex and risky procedure that involves rooting your phone.)

If traditional tethering is what you're after, though -- connecting one device to your phone at a time via USB or Bluetooth -- that's something you can do very easily without paying a dime. In fact, you can do it regardless of what Android phone you're using or what version of Android you're on. Just don't tell your iPhone-toting friends.

[Related: When's your phone getting the Android 2.2 upgrade?]

Here's a five-minute guide to tethering with your Android phone. And remember, if you have an Android-related question of your own, send it in to ask@androidpower.com. I'll answer it here soon.

Android Tethering: Words of Warning

First, a quick caveat: Some carriers may object to tethering. They may scream, cry, issue a nominal fee, or possibly even string you up by your toes if they discover you're doing it. Others don't mind so much. And, just between you and me, most carriers won't actually know you're tethering unless you suddenly start downloading copious amounts of data over your newfound connection.

Finally, not to name any names, but one carrier in particular (cough cough, AT&T) tends to restrict what its users can and can't install on their Android phones, thereby defeating one of the core principles of the Android platform. If you're on this carrier, you may run into trouble finding and installing apps related to tethering. There are some backdoor workarounds, but they're a bit on the advanced side (hint: the SIM card is what tells your phone it's connected to AT&T), so you'll have to decide what you want to do.

Long story short, make sure you read the fine print of your carrier's wireless usage agreement, and proceed at your own risk. Capisce?

Android Tethering: Preparing Your Phone

All right, ready to get on with it? There are several ways you can go about tethering your Android phone. I'm going to focus on the one I've found to be the quickest and easiest, not to mention the least wallet-draining (you know, because it's free).

First, head over to the Android Market and search for "PdaNet," or scan the barcode at right for instant access. Go ahead and install that bad-boy to your phone.

Now, on whatever computer you want to use for tethering, click over to the PdaNet Web site and download the companion PC program. You'll find options for Windows XP, Windows Vista, Windows 7, and Mac OS 10.5 and 10.6. The basic edition of the PdaNet PC utility is free, though if you need to access secure (https) Web sites during your tethering, you will have to spring for the paid edition.

So far so good, eh? Well, grab a cold beverage: You're done with the heavy lifting and ready to tether.

Android Tethering: Starting Your Connection

Once you're ready to actually begin a tethering connection, you need to adjust one little setting on your Android phone: Tap your phone's Menu key and select Settings, then Applications, then Development. Now check the box that says "USB Debugging" and press "OK" when the confirmation box appears. This will allow the PdaNet app to directly stream data from your phone to your PC. Be sure to go back into this same menu and turn it off when you're done using the tethering function.

At this point, you're ready to plug your Android phone into your PC via USB. Once it's connected, run the PdaNet app on your phone and select the "Enable USB Tether" option on the program's main screen. (You'll also notice an option for Bluetooth-based connections; if your computer has Bluetooth capabilities, you can select this to connect to your PC wirelessly instead of using USB.)

The app will now tell you that it's on and running as a background service. Next, just head over to your PC and find the PdaNet icon. On Windows machines, it'll be a rectangular cell-phone-like symbol in your system tray. Right-click the icon and select "Connect" from the pop-up menu.

That's it -- you're done! Your PC is officially tethered to your Android phone, and you should be able to surf the Web at will using your phone's 3G or 4G connection.

That, my friends, is Android power.

Author JR Raphael writes the new Android Power blog at Computerworld. You can find him on Facebook: facebook.com/The.JR.Raphael

This story, "How To Tether Your Android Phone For Free" was originally published by Computerworld .