TradeHill
Was at its height the second largest bitcoin currency exchange site.
History
First mention on the site was on June 8th, 2011[1] which is also the "go live" date display on the exchange's status page[2].
On July 25, 2011 the exchange reported anomalies with Dwolla payments and stopped accepting Dwolla for deposits[3].
On August 10, 2011 the exchange resumed providing methods for SEPA transfers for deposit and withdrawal[4].
On February 13, 2012 the exchange announced it was shutting down[5].