Total n00b here, I JBroke my iPhone 4 on 4.2.1 for the first time yesterday (I'm in Italy, so no need for unlocks here).
Before doing it, I saved my SHSH blobs with TinyUmbrella and its logs said they were also uploaded to Cydia (which seemed weird to me, as I hadn't installed it yet).
When I finally did, Cydia didn't ask me to "make my life easier", and had a green "SHSH: iOS 4.2.1" up in the middle.
Does this mean my blobs are already on the server?
Also, what are you people using, besides iTunes, to transfer stuff from/to your device?
By the way, Backgrounder is AWESOME. Goodbye disconnections from IRC after 10 minutes of background inactivity. Welcome actual multitasking.