yes, I tried usb drive as you said, and I've just found out several portable apps at download site, prayaya v3,ceedo, seems that still have another sandisk U3,
I tried install MSN messenger in the prayaya V3 platform in usb drive, and I solved this problem, it works in usb drive just like I'm working in my own computer, my chatting history will show everytime if I use my drive, great, hum, I think I need a higer capacity usb drive now.