bytemap, no we do not support "proxy bidding" (the thing that eBay uses where it only increments up to your current bid). The reason is twofold, but I mainly am not a fan of the system myself. I like people to know exactly what they're bidding, and it encourages more back-and-forth bidding in the spirit of the traditional lowballs. I'm sure I could figure out how to program proxy bidding, but for now I am going to stay away from it.
Thanks for your comments!