CashArena is a new penny auction that has taken the small world of penny auctions quite by storm because instead of auctioning off products like most penny auctions do, CashArena auctions only pure cash. The site is extremely well made and is very different from all other penny auction sites. In addition, they have a number of other ways in which you can win (e.g. Coloritas at their site).
For a limited time, CashArena has a great promotion to new members - 50% free bids! I didn't find any coupon code for the site, so it is a big deal. The CashArena coupon code is SIDBLOG. You can use it the first time you buy bids and get 50% free bids at CashArena. This will drastically reduce the overall price you spend for the bids (you can mail them the coupon code or just contact support to redeem it)
If you are interested, you can read my interview with Hilary of CashArena to know more about the site and the business. Check out CashArena for a totally different penny auction experience.