Adding a wireless USB modem to your Eee PC (or any other ultra-compact notebook) makes it a true go-anywhere machine, but there's one slight nuisance: you're left with a modem hanging off the side.
Not necessarily a problem on your desk at home, but on a crowded train or in the back of the taxi it can quickly become a real nuisance as it bounces around. Conventional notebook owners can eliminate that hassle with a PC Card, but that's not an option with most ultra-portables.
My simple (if not entirely elegant) solution to this conundrum was to whack a medium Command Picture Hanging Strip on the back of the modem, and another one onto the back of the Eee screen on the bottom right-hand side (nearest the USB port). The velcro-like attachments let you fix the modem easily in place when you need it (be careful not to apply direct pressure to the display itself), and the standard short cable that comes with pretty much every USB modem covers the distance nicely without excess.