One of the things I never liked about my iPad is the requirement to have a separate charger and that it couldn't charge from a standard USB port.
ASUS has come out with a driver that allows this. I've installed this and now my iPad, instead of saying "Not Charging" while plugged into my PC, has the plugged in symbol. I have not yet determined how long it takes to charge etc.
This is working fine for me but I did run into some comments on the web about crashes etc. so it's probably a good idea to set a system restore point prior to installation.
Although officially designed for ASUS brand PCs and Motherboards, it seems to work on just about any brand. Mine's an EVGA brand running Windows 7. Many others on the web are also reporting success on non-ASUS products.
http://event.asus.com/mb/2010/ai_charger/
[Edit]
Just tried it on my Dell Latitude D630 laptop also running Win7. Seems to work fine.
Tom