The iPhone Dev-Team Blog, known for posting news about the status of iPhone jailbreaks, reports that a new untethered jailbreak is available for non-A5 devices, meaning the iPhone 4S and iPad 2 are unfortunately not included in this release.
An untethered jailbreak means that you can reboot your jailbroken device without needing to connect to a computer with USB, which is obviously desirable in situations where you might not have access to a computer.
The author of this jailbreak, @pod2g, is now working on a method to jailbreak A5 devices. The full list of supported devices includes the iPhone 3GS, iPhone 4, iPhone 4-CDMA, iPad 1, iPod Touch 3G, and iPod Touch 4G. This jailbreak will require your device to already be updated to official iOS 5.0.1, which is okay because the window for signing SHSH blobs is still open for 5.0.1. The iPhone Dev-Team Blog has links to official downloads for PwnageTool and redsn0w for those interested in jailbreaking their devices.
While jailbreaking can of course be used to pirate apps and gain access to content without paying for it, the real appeal for some technology enthusiasts is the actual freeing of the device with access to SSH and exciting apps that aren't available on Apple's App Store. I haven't had a jailbroken device since the iOS 5 release because I found the improvements to be worth losing the jailbreak capabilities, but I might consider jailbreaking again simply for great apps like SBSettings, BiteSMS and iBlacklist.