In conjunction with iOS5 beta4 being released to iOS developers, redsn0w 0.9.8b4 is now available for jailbreak app developers. Remember, it's a tethered jailbreak right now so you'll need to use redsn0w to boot into a jailbroken state at each power cycle.
NOTE: It appears that by design, the OTA update that became available starting with iOS 5 beta4 will *not* be automatically applied to jailbroken devices. That's a relief to those who don't want to lose their jailbreak via OTA pushes. If you're jailbroken, you'll need to use the standard iTunes method to get to iOS 5 beta4.
You can download the new version of RedSn0w from here: Windows, Mac.
You can find instructions on to use RedSn0w to jailbreak iOS 5 below. Remember to use the new version of the software. We'll update the links in the tutorials shortly.
● iPhone 4 (Windows, Mac)
● iPhone 3GS (Windows, Mac)
● iPad 1 (Windows, Mac)
● iPod touch 4G (Windows, Mac)
● iPod touch 3G (Windows, Mac)