#3. "RE: Battery Grip for Nikon D3100" In response to In response to 0 Fri 07-Sep-12 12:32 AM by MontyG
Try this one. I just got the Vello grip for the D5100 and like it. I also ordered an aftermarket battery for $7, which should work just fine as long as a real Nikon battery is also present in the grip.
The Vello grips are more expensive, but the color, texture, and rubber grip on mine matches my camera perfectly.