Hi, I also using iphone 4 OS 4.2.1. I've jailbroken successfully. I can download any apps now. But my problem is, my cydia dun seems to be working. Everytime i open, it brings up the window and then closes itself. What can Cydia do? Is it useful? So a tethered jailbreak is not good? I cannot use any laptop without redsnow to charge my iphone battery? I had been using normal plug charger for the past few days, it can be charged leh. Please help me. I'm new to apple products.