
Step 1: Download the latest version of TinyUmbrella (Windows, Mac, Linux), and make sure you're running iTunes 10 on your PC or Mac.
Step 2: Launch TinyUmbrella and connect your iOS device to your PC / Mac. Now select ‘Advanced Option’. Your ECID number should already be there, and make sure ‘Location’ is set to ‘Cydia’
Step 3: Now just click on ‘Save My SHSH’ and wait a few seconds

Well done, now you got your SHSH blobs saved.