After iOS 4.3.2 was released the jailbreak everyone was waiting for was released, yes we are talking about the untethered jailbreak using RedSn0w, well below you can see the how to jailbreak iOS 4.3.2 using RedSn0w.
iDB has a quick step by step how to jailbreak iOS 4.3.2 using RedSn0w for you iPhone, this does not work on the Apple iPad 2, another words it works on all devices on iOS 4.3.2 other that the iPad 2.
If you would like to use RedSn0w you must be on firmware 4.3.2 that means you will be able to update your baseband, if you need your unlock it has been suggested you do not use RedSn0w, just wait for PwnageTool.
RedSn0w is having a few problems with the iPhone 4 and we would love to hear from those that are experiencing issues. The how to instructions is fairly simple starting of with you needs the latest version of iTunes installed, your device must have the latest 4.3.2. Visit iDB to download the iOS 4.3.2 and RedSn0w.
Please visit the iPhone Download Blog (iDB) for the full instructions, if you do get stuck on the Apple logo on your iPhone 4 please visit this page. You may wish to check out the RedSn0w Jailbreak [Tethered Jailbreak] YouTube video guide below this article (via spiritjb.org)