The lack of a real USB capability on the N800 (and 770) has always been a serious disadvantage, but it seems to be due to USB's power requirements (i.e. probably also true of any handheld device).

The PepperPad 3 is similar to the N800 in that out of the box WiFi is the only high speed network option, but it does have two standard USB ports. They sometimes fail to work with power hungry disk drives, but otherwise they are great for expandability. In particular, several Ethernet over USB adapters work with no changes to the system setup. According to umpcportal.com battery capacities are 5.5 W/hr for the N800 vs 28 W/hr for the PepperPad. The N800 is much more efficient (runs longer on its smaller battery), but lack of USB ports is one trade-off for low power.