The
Dev-Team has already upgraded its
Redsn0w 0.9.8b5 to jailbreak iOS 5 beta 5.
As for the previous iOS 5, the jailbreak is possible but it’s tethered, meaning that you have to plugin your iOS device to the computer and boot it in tethered mode using Redn0w.
Please note that you’ll not be able to unlock your iPhone using this method. An unlock for iOS 5 is still not possible.
This jailbreak does not work for iPad 2. If you have an iPad 2 jailbroken with
JailbreakMe 3.0, stick to it because an untethered jailbreak for iPad 2 will not be available for a while.
This jailbreak will work on
iPhone 3GS, iPhone 4,
iPod touch (third and fourth generation) and
iPad 1.
To legally download iOS 5 and
iTunes 10.5 Beta 5, you need an Apple developer account which is available to anyone willing to pay $99/year.
If you need a tutorial for the jailbreak, it’s found
here. If you need to know how to boot in tethered mode, look
here
Download
Redsn0w 0.9.8b5 for Mac
Download
Redsn0w 0.9.8b5 for Win 
BR
GsmUniversal