Rumors are flying all over about Apple releasing the iOS 4.0.2 firmware for iPhones and iPod touches and iOS 3.2.2 for iPad in a few hours from now. This update is being released to patch up the PDF exploit which is used by JailbreakMe to jailbreak all iOS devices. Accidental update to iOS 4.0.2 / iOS 3.2.2, will make it impossible to jailbreak and unlock straight away until a new tool comes handy. The only way you can jailbreak again will be by downgrading back to iOS 4.0.1 or iOS 4 for which you will need your SHSH blobs, so better save them now.

TinyUmbrella

To save SHSH blobs, follow procedure posted here.         [Via Redmond Pie]