I don't know if anyone is interested, but I've just worked out how to get an rt2870 WiFi USB dongle working with debian. Please excuse my nativity but until yesterday I'd never played with linux, rpi or debian.
As far as I can tell the distribution ends up with the wrong firmware (a 4k version of rt2870.bin rather than an 8k version). If you replace the .bin file with a suitable good one, wifi leaps into life.
Here's a quick rune summary of what I did (sudo / su permitting):
# Install wireless
change "deb http://ftp.us.debian.org/debian
squeeze main" to "deb http://ftp.us.debian.org/debian
squeeze main contrib non-free"
aptitude update && aptitude install firmware-ralink wireless-tools
aptitude install wicd
cp /mnt/myusb/rt2870.bin /lib/firmware
# Connect to a WiFi network
# Connect at start-up
iface wlan0 inet dhcp
Hope it helps - caused me a little bit of a headache. Same headache appears in the Fedora remix except all that needs patching there is rt2870.bin and then a reboot.
Apologies if this isn't useful / involved egg sucking.