The iPod is a deeply personal device. The music, contacts, calendars and notes you store on it reveal much about your personality. From playcounts to playlists, our iPods can tell others what we enjoy, how we think and even who we are. But if you truly want to transform your iPod into an engine of extreme personal expression, why not customize it?

Hacking an iPod—whether it’s modding the case, installing custom software, or tearing it up and doubling the memory—can transform the ubiquitous music and media player into something unique. Once again, Playlist has scoured to net to find the hottest iPod hacks, mods and customizations. As always, you should be aware that trying any of these tricks carries the risk of ruining your device. We present these for the curious, but urge you to exercise caution before even considering any of them. Keep in mind that if you crack open your iPod and destroy it in the process, Apple isn’t going to take pity on you. In other words, don’t try this at home.

1. Penguin Power

We went over this customization in our last look at iPod hacks, but we’re featuring it again as iPod Linux is the essential hack, table stakes for many of the other hacks you might want to try. It’s fully supports iPods in generations 1-3, and has been successfully installed on all others with a display—which doesn’t necessarily indicate that you’ll be successful yourself. You should also grab a copy of Podzilla, which will add a graphical interface to iPod Linux. There are multiple flavors of Podzilla available for you to choose from. Once installed, iPod Linux and Podzilla will let you boot up your iPod to a bare-bones Linux mode. Furthermore, it will serve as the foundation for many other hacks, both ones listed here and those in our previous guide.

2. Knowledge to Go

Everyone loves Wikipedia. It’s the free user-built encyclopedia with entries on more topics than Britannica. It’s a great information resource, but what if you’re away from your desk? Now you can get it on your iPod and carry Wikipedia with you everywhere you go. Unfortunately, it’s not yet available for all models of iPods, nano and video users are left out for now. (And obviously, since there is no display on the iPod shuffle, there is no point to installing Wikipedia.) You first will need to install iPod Linux.

3. Double your Damage

One of the two most daring iPod hacks we’ve come across was this build featured on multiarcade. Not content with the 4GB of memory iPod nano? So why not double it. Not for the faint of heart, performing this hack requires that you conduct some major surgery on your nano. First you’ll need to buy a broken nano from eBay. Next up, crack it open and remove the memory. Then, and here’s where it gets really dicey, you’re going to want to open up your working nano. Finally, you’ll solder the memory chip from the broken nano to the empty pad in the working one, seal it back up, and perform a factory reset. You’ll now either have one working nano with 7.2 GB of space, or two useless ones. Either way, this courageous hack should make for a fun-filled weekend project.

4. Mobile Movies

If you have a lot of movies on DVD, odds are you’ve thought of transferring them to your iPod. Doing so is relatively easy using free software available for both the Mac and Windows. Be warned: unless you use an analog capture method, the DMCA makes it illegal for you to take the movies you own on DVD and put them on your iPod.

For Mac (and Linux) users, the process couldn’t be easier. All you need is a copy of the free utility Handbrake. Handbrake is already available as a Universal binary—good news for those who have a new Mac Book Pro, Mac mini, or iMac—and can rip video from DVD directly to mpeg-4 video, the format you’ll need to watch it on your iPod.

Windows users need to make a few extra steps. First, you’ll need to find a DVD ripping program, such as DVDFab Decrypter or DVD Decrypter. Next, you’ll want to convert your video to AVI using a decoding tool. Finally, it’s time to convert that AVI file into mpeg-4 video that can play on your iPod, Videora iPod Converter is a great tool for this last step.

5. iPod to TV on the Cheap

This hack is almost the reverse of the previous one, at least in terms of what it accomplishes. Want to watch content from your iPod on your TV? You can easily do so by purchasing the $19 iPod AV cable from Apple. But where’s the fun in that? Apple notes that other AV cables are not compatible with iPods with color displays. But that’s not completely true. You can accomplish the same task using a standard mini-jack to three-plug RCA cable. Since these cables tend to run southwards of ten bucks, it makes for a slightly cheaper way watch your iPod videos on your TV set. Set your iPod to output to TV, plug in the cable via the minijack, and you’re nearly there. The final step is to simply plug the RCA connections into your TV using a non-standard setup. Apple outputs the iPod’s video to the red cable—rather than the traditional yellow. So you’ll want to plug the red cable into the video (yellow) plug on your TV, the yellow cable into the white plug, and the white cable into the red plug. This is an easy hack that anyone with an iPod video can try.

6. Pac Attack

Growing up, I spent endless hours in front of an arcade console, popping pills and running from ghosts. Now I can re-live those glory days with my iPod, thanks to iPodMAME, which allows me to play Pac-Man right on my iPod. This hack will install a version of MAME, the arcade game emulator program, on your iPod. As with the Wikipedia hack, iPodMAME requires that you first install iPodLinux. The program comes with romsets (the set of files including all the game data) including one for Pac-Man, however others should be able to be added. To date, iPodMAME has only been tested on the 5G iPod with video and the iPod nano, but the creator notes that it should work on any iPod with a color screen.

7. Radio Free Shuffle

As always, Jim Younkin’s Shufflehacks site is a great source of inspiration. And one of the recent hacks he posted was no exception. This risk-free hack will let you turn your iPod shuffle into a portable radio station—perfect for taking your shuffle with you on a road trip. The build notes offer instructions on how to build a radio transmitter that plugs into your shuffle (or other MP3 player). The example on Shufflehacks uses a computer mouse for a body to house the radio, perfect for an über-geeky customization.

8. Scratchless Super Screen

There are only two complaints we hear about the iPod with any degree of regularity. The first is that the screens can be easily scratched, and the second is that they’re all the same. This hack takes care of both of those complaints. Note that we include this last mod not because we think you should try it (we don’t!), but rather because it’s so daring. Like the memory doubling hack featured above, this is a good way to ruin your iPod. But that didn’t stop Seth Fogie from cracking open his iPod and scratch-proofing the display. Noting that the faceplate on the Sony PSP is more bulletproof than that on the iPod, and that it nearly matched the iPod’s in terms of size, Fogie set about swapping the two of them out. Fogie completely disassembled his iPod, and then filed down his PSP faceplate to fit. After re-assembling everything, he was left with a “Scratchproof” iPod. While we don’t suggest you try this at home, we’d love to hear about it if you do.

Mathew Honan is a San Francisco-based technology writer whose work has also appeared in Macworld, Salon, and Wired. You can check out his Mac and iPod weblog at mac.honan.net