GeoHot is probably the most popular man at the moment. Why? Because he just released a jailbreak for the new iPhone 3GS on OS 3.0 unlike the Dev Team who insisted on waiting until firmware 3.1 to release their version. It is called Purplera1n.
Here is what GeoHot says about how to use it:
Download it. Make sure you have windows(but not 7), the latest iTunes installed, and an iPhone 3GS with 3.0 firmware. Connect your iPhone normally. Click “make it ra1n”. Wait. On bootup, run Freeze, the purplera1n installer app. Hopefully you’ll figure out what to do from there.
GeoHot, or George Hotz, has even offer a phone hotline where you can call for support on the program. It is 650) 265-1210. There is also an email: purplera1n.support(at)gmail(dot)com.
Sadly for Mac users, they are going to have to wait because this jailbreak is currently only for WINDOWS. This is in BETA!
Click to download: Purplera1n - iPhone 3GS Jailbreak (79)