It never charges when I have it plugged into my computer USB port. Is this because it requires current directly from a wall plugin and the USB port doesn't generate emough juice?
I see there are two threads going with this same question. I don't know if the moderators merge these threads. Short answer, computers don't generate enough power and wall charging is necessary.
Because the iPad has a much higher capacity battery it requires a more powerful charger. Even though it says it's not charging on the USB port it really is but VERY slowly. It is highly recommended that you only use the Apple provided wall charger for the iPad.