PsychoAuction is a very small penny auction site. PsychoAuction auctions last 5 minutes.

BidTrotter is a small Penny Auction Site.  BidTrotter has one unique feature: if you're the 2nd place "loser" in an auction, you can get 25% of your bids back, provided you bid 100 times on that auction.

Nickelbids is a small Penny Auction Site. Nickelbids has a public support/ticketing system that provides a lot more transparency than most penny auction sites.

Bidaroo is a small Highest Unique Bid Auction headquartered in Indiana, USA.  Bidaroo donates 25% of proceeds to various charities.

BidRodeo is a medium sized Penny Auction site.  BidRodeo is your typical penny auction site, offering a wide range of products, such as electronics and gift cards, they even auction off gold bars.

Dubli is a medium sized penny auction site that is also part of an MLM (multilevel marketing) company. Dubli offers Lowest Unique Bid and View Price Auctions.

Bidz is a very large discount auction, selling mostly jewelry and watches at significant discounts.  Bidz is not a penny auction, however, it is very popular with consumers looking for big discounts on large ticket items, similar to penny auctions.

Winnit is a Lowest Unique Bid penny auction based in the United States.  Winnit is currently best known for hiring Nick Lachey to act as their spokesperson.

Famdabidosy Auctions is a small United States based Penny Auction site. Famdabidosy Auctions offers 10% cash back for friend referrals and hosts Set Price, Totally Free and Night Auctions.

BidHere is an Australia based Penny Auction site. BidHere offers a wide variety of auction features, such as Cash Back, Speed and $0 auctions.

Winners24 is a small, United States based Penny Auction site. Winners24 offers Free Shipping on all items worldwide and activates new auctions every 30 minutes.

BidCactus is a large, United States based Penny Auction site. BidCactus auctions are open from 9 am to 5 pm Eastern Time, Monday through Friday. BidCactus offers specials such as Wacky Wednesdays and Happy hour Fridays.