iPhone Dev team has provided a tethered jailbreak solution, Redsn0w 0.9.8b4, for previously released iOS 5 Beta 4 software update. If you are a jailbreak user and iOS Developer, you can safely use Redsn0w 0.9.8b4 tool to get the jailbreak facility on your iDevices.
Please read this official note from jailbreak tool developers -
In conjunction with iOS5 beta4 being released to iOS developers, redsn0w 0.9.8b4 is now available for jailbreak app developers (point the b4 redsn0w at the b4 IPSW). 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.
As said earlier, Redsn0w 0.9.8b4 is a tethered jailbreak. If you want an untethered jailbreak for your iDevice, you may have to wait till the iOS 5 final release.
Download Redsn0w 0.9.8b4 to jailbreak iOS 5 Beta 4
[We've removed the downloadable links from our site due to policy violation issues. Sorry for the inconvenience.]