Lisa -- what did you end up going with? We used Auction! last year, and I'm just started to research for our 2014 auction... Trying to decide whether to stick with the same thing or go with technology.
BidPal can still work with a large group and now that they have a SmartPhone bidding option (Android and iPhones) it's even better. BidPal is fabulous and a complete solution (credit card processing, online auction/registration/ticket sales, bidding automation and event management software). You should consider it for your next carnival.
Has anyone used Auction Star's software - it is a barcoded system that has barcodes for the item, and bidder, and closeout is a matter of scanning? We have used Auction! software for years, and are looking at making closing simpler. Can't use BidPal, as we have the auction during a carnival that the community attends, so there would be too many people in and out of the event.