Wireless connectivity to the garage PC is proving a challenge. The USB ports are a mix (WTF?) or 1.1 and 2.0 and the only PCI slot is a low-profile one. To top it all off, with the rollerdoor down the PC is basically inside a huge RF-shielding box!
PCI - does *anyone* make a low-profile PCI 802.11b/g card?! Arrrggh! If I could get one of these with a low-profile bracket it would be a simple matter to whack an outdoor antenna on the outside of the garage and get a good signal.
USB - offers a lot of flexibility in terms of placement of the dongle (ie at the end of a long USB cable poking outside the garage), but I'm not convinced that running any sort of network over USB is all that stable. But it might make a good last resort.
Ethernet Bridge - excellent possibilities, however, ones with weatherproof housings start at AUD$1200 (OUCH!)
So... the interim solution - steal the grunty Netgear WGE111 bridge from the XBox in the living room and see how it performs.