I have a Belkin USB 2.0 card in my beige G3. It is called Belkin F5U220 (see http://www.belkin.com/IWCatProductPage.process?Product_Id=107412). I heard for maximum Mac compatibility one should go for a card with a NEC D720101GJ chip (like this Belkin). I'm using these extensions:

HID Library 1.4.6 
Serial ShimLib 1.4.6 
USB Device Extension 1.4.6 
USB Mass Storage Support 2.0.9 
USB Software Locator 1.4.6 
USB Support 1.4.6
 
HTH, bobo68
 
P.S. I'm pretty sure the Belkin runs with USB 2-0 speeds but I would have to check.