Jailbreaking an iphone can and usually will take awhile depending on how u jailbroke it. It sometimes doesnt work the first time either. I jailbroke my first iphone, the original one. I now i have the new one and if you do also, there really isnt that great of a reason to jailbreak it. Many talented people have been creating applications for the iphone and new ones keep being made daily. Its better to be safe and not jailbreak the phone and just use the applications that are on the app store. Also, if you jailbreak your phone and something happens to it, be sure to undue the jailbreak before you take it to the genius bar to be repaired. If you dont, they will NOT fix it. But to fully answer your question, leave it plugged in and let it sit for awhile.