I’ve started using AuctionSniper.com to do my ebay bidding. It didn’t work the first time I’ve tried it but I have since won auctions at bargain prices.

A nice feature is bidding groups. Here you can bid on a group of items until you have won enough. For example if you want a hard-drive, you would look on ebay for any hard-drives you would like, give a max bid for each and auctionsniper will keep last-minute bidding on each of the items until you have won one.