How long it takes to charge depends on the power output of the port. My HP Pavilion notebook charges faster than my wall charger.
Posted from my CrackBerry at wapforums.crackberry.com
Listen to redbound, all USB ports are not created equal, some provide enough current to charge your phone and some don't. My laptop docking station will charge my phone just as fast as a wall charger but the ports on the laptop don't.