I have a "Sweet Multiport" by Gee Three which fits all models of G4 & G3 smurfs. It has firewire 400, USB and memory card (SD, CF, memory stick) ports on the front. The PCI card it comes with is USB 1.1 so I use a newer USB 2 card with an internal port to power it. The kit sold for about $50 new. They're hard to find now, try the LEM swap list (Google Group).