Jailbreaking or rooting your phone is pretty much a nerd birthright at this point. But soon it could once again be deemed illegal, if the acts' exemption to the Digital Millennium Copyright Act runs out. That's where you come in.
If that exemption runs out, it would be illegal to install a clean version of Android over top of carrier junkware or to jailbreak an iPhone so you can download apps outside of Apple's walled garden. Apple's fought especially hard to keep jailbreaking on the periphery of iOS, and we'd expect nothing less than a concerted effort on its part to stand in the way of an extension for the DMCA exception.
The other thing to take note of? Seems the original exemption didn't cover the iPad (or presumably other tablets). It doesn't make much sense, but it's the letter not the spirit of the law that'll bring the hammer down on you if anyone ever decides to get litigious about software modders of the world.
While we've gone over all the reasons that jailbreaking being made legal wasn't the biggest deal functionality-wise, it would still be nice to know that you're not going to get locked up for downloading a few ROMs. Head over to the EFF to show your support on the petition to get the exemption extended, and expanded to tablets. [Charlie Miller, EFF, Redmond Pie via Techmeme]