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

Auctions4aCause is a United States based Highest Unique Bid auction.  According to Auctions4aCause, charities of your choice receive at least 25% of the net proceeds from 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.

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.