“The emergence of services that mingle bitcoin for the purpose of returning bitcoin not associated with the original input address has had a somewhat spotty history. Also called bitcoin laundries, these web-based services charge bitcoin holders a nominal fee to receive different bitcoins than the ones initially transferred. The largest such service operating today is the Blockchain.info mixing service which has a maximum transaction size of 250 bitcoins and a 0.5% transaction fee. Other services include BitLaundry and The Bitcoin Laundry operated by Mike Gogulski.”
http://www.forbes.com/sites/jonmatonis/2013/06/05/the-politics-of-bitcoin-mixing-services/
