Will jailbreaking my iPod void my warranty?

Mhmm, it voids the waranty but it’s well worth it. I could’t have waited for the SDK to come out…
The 3rd party apps are quite remarkable, I wouldn’t say I know exactly what happens when you restore your iPod touch in iTunes…but I’m guessing it will overwright installer.app, thus hiding that you voided your warranty.
Besides that, installer.app is amazing, I’m posting this on my iPod touch right now!

I’m not sure it does void the warranty. It’s not making a hardware change, just changing some software.

See this question:
What is jailbreak for ipod touch?

notably, paulc’s answer. If it does void the warranty you’d be able to restore to an old version of the firmware.and everything will be peachy.

what specific 3rd party apps make doing this worthwhile?

Yahtzee.

Well, IM applications, as well as the possibility to add the iPhone apps Mail, Maps, Weather and Stocks to your iPod Touch

Yes, it technically voids you warranty. But nothing a restore doesn’t fix.

If all you want is IM, I find Meebo works beautifully. I’d jailbreak it for a Skype client though.

Don’t use Meebo for the iPhone, use BeeJive. Its the closest thing you’ll get to iChat. My phone is jailbroken I and vastly prefer BeeJive’s webapp to Apollo.

I love meebo and beejive, but Apollo is still the best because I can run it in the background while surfing. Least for me…

Yeah, just don’t bring it in for service with it jailbroken. The Apple people will look at you like you are on drugs!

Always do a restore if you bring it in for service.

Also, it’s almost impossible to Brick and iPod touch or iPhone because they possess a little thing called recovery mode :)