I had and still have ( although it doesn't work too welll ! ) a G3 Wallstreet Powerbook. As it didn't have USB ports, i was told that it was impossible to upgrade is to OSX, so it was running with 9.6 ( IIRC ).
Anyway, i bought quite a cheap PCMCIA card from eBay, which acts as a four way USB hub, and this worked quite well. THere is a bit of software needed that acts as a driver and this can be downloaded - if you run a search on this forum, you will find the link for the driver.
It worked quite well, I was able to attached USB devices such as a plug n play MP3 player and USB Memory devices. Didn't try anything like camera's or iPods though.