You can get the latest drivers that do work on Mac OS X 10.4.7 Tiger at
http://www.factman.com/USB_Wireless_Installer.dmg
This driver came today 7/20/06 direct from the Ralink engineer, and it for sure works.
Further, if you are looking for the longest range wifi connection for your mac, go with the usb antenna/Ralink card combo (there are different sizes antennas, but same 802.11g card from this guy in Canada found at:
http://stores.ebay.com/Wireless-Online-Depot
I'm bought the 4 inch square usb version for under $100 (28dbm) and the larger 14 x 15 inch version (38dbm) at about $120.
My new MacBook Pro has the smaller Expresscard/34 slot, which is useless for wifi, since there are no cards available yet. The above Superpass antenna/cards (
http://www.superpass.com/Superusb.html) are definitely the way to go for Mac. They are convenient, portable, and have the high output usb radio card built inside the antenna box. Neat!