The iPhone Dev-Team recently released RedSn0w 0.9.8b7 which brings explicit support for a tethered 4.3.5 jailbreak as well as new iOS 5.0b6 iPad 1 jailbreak:
Apple updated the iPad1 iOS5b6 IPSW without changing its version number or filename, so we’re releasing redsn0w 0.9.8b7 to handle both the original and changed IPSW. We’ve also added explicit support for a tethered 4.3.5/4.2.10 jailbreak (instead of pointing at the 4.3.4/4.2.9 IPSWs) and fixed a 4.2.10 problem.
We’ve released redsn0w 0.9.8b6 to jailbreak iOS5 beta6 (point it directly at the beta6 IPSW).
Two important notes about this version:
(1) Please let your device boot normally to IOS5b6 and do a clean shutdown (slide to power off) before jailbreaking.
(2) Boot logos have intentionally been disabled for now, so you’ll see a black screen on tethered boots (you can re-enable logos or verbose boot with command-line options if you really want them back).
Due increased sensitivity to abrupt filesystem shutdowns in IOS5b6, it’s very important that you do a clean shutdown before running redsn0w.
RedSn0w can perform a tethered jailbreak on iOS 4.3.5 for all devices except the iPad 2, according to MuscleNerd’s tweet:
So those who really do want tethered 4.3.5 can use redsn0w pointed at 4.3.4 (except iPad2)
We strongly recommend NOT to update to iOS 4.3.4 or iOS 4.3.5 to preserve untethered jailbreak. We will soon post step-by-step tutorials on how to perform iOS 4.3.5 tethered jailbreak.