Semaphore has updated TinyUmbrella (4.1.13) to allow for the saving of iOS 4.2b3 SHSH blobs for the iPhone, iPod Touch, and the iPad. This is the first time SHSH blobs are being saved for a beta release and the significance is as of yet unknown, but semaphore tweeted that it might be used to assist the untethering of future jailbreaks. Since the release of iOS 4.2 is imminent, iOS 4.2b3 signatures will not be available for long.

You can download TinyUmbrella from the link below to save both iOS 4.1 and iOS 4.2b3 SHSH blobs regardless of what firmware you are currently on and I recommend doing so immediately just in case they are needed down the line...

[TinyUmbrella]