Jailbreakme.com is finally up in its 3.0 iteration with support for iPad 2. Yes, iPad 2 was the only iDevice without a jailbreak but not anymore. Comex is the guy behind jailbreakme.com.
The following devices+iOS versions are currently supported :

iPad1: 4.3 through 4.3.3
iPad2: 4.3.3
iPhone3GS: 4.3 through 4.3.3
iPhone4: 4.3 through 4.3.3
iPhone4-CDMA: 4.2.6 through 4.2.8
iPod touch 3g: 4.3, 4.3.2, 4.3.3
iPod touch 4g: 4.3 through 4.3.3

The beauty of this jailbreak is that it is completely cable-free. All you need is an activated device (iPhone) or iPad or iPod Touch. If you are stuck at bootscreen …

Apple just released iOS 4.1 update, not a super important update for 3GS users (unless you are into GameCenter!). iPhone 4 users can finally relax given that iOS 4.1 comes packaged with a fix for those nasty sensor issues.

Before you do any thing, please quit iTunes and do the following. TinyUmbrella is what you need to save your iPhone from Apple’s anti-jailbreak updates.
Download TinyUmbrella for your Mac/Windows/Linux.
Install/Launch TinyUmbrella and save SHSH blobs for iOS 4.0.2 for 3GS, iPhone 4 from Apple (or Cydia after the SHSH blob signing period by …

iPhone 4 was recently jailbroken and now it is unlocked too, thanks to the Dev Team. It cannot be easier, no PC/Mac required, only the internets!
All you need are the following :

A Jailbroken iPhone 4 / 3GS,3G (it should be activated, that is a pre-req for online jailbreak)
A WiFi connection
That is pretty much it!

Step by step (best practices) :

Launch Cydia and search for ultrasn0w [if not found, then add repo : repo666.ultrasn0w.com in Cydia]
Install ultrasn0w and reboot your iPhone 4 when prompted. Turn 3G off  (Settings -> Network -> Enable …