Apple may have tightened the security on the iOS 4.3 with the .1 update, but the developers have beaten them once again. The new redsn0w version is out and it jailbreaks every Apple device running (officially) iOS 4.3.1, but the iPad 2 and the CDMA iPhone 4.
You can get the new redsn0w 0.9.6rc9 from the Dev-Team blog and free your device. It supports iPhone 3GS, iPhone 4 (GSM only), iPad, iPod Touch 3G and 4G). The AppleTV 2 jailbreak is done via the new Pwnage Tool, which was also released today.
If you need unlock solution, you must stay away from updating just now. For 4.3.1 you will need a new version of the ultrasn0w tool, which is still cooking but should be available soon.