UCO - ProShares Ultra DJ Crude Oil ETF is the only leveraged long crude oil ETF available right now due to the closing of DXO by PowerShares in September 2009 due to restrictions on the size of futures positions.  The goal of UCO is to provide 200% of the daily performance of the Dow Jones UBS Crude Oil Sub-Index.

UCO began trading on 11/24/08 and has an annual expense ratio of .95% (95 Basis Points), similar to other ProShare Leveraged ETFs.  It has roughly $370 million in assets and trades about 5 million shares per day making it an extremely liquid Oil ETF for trading.

You can see that right after UCO started trading crude oil had a sharp decline so it has been under water versus the USO right from the start of trading.

UCO Performance Since Inception VS USO

 
Chart begins the first trading day of UCO

If you purchased UCO at the low in August 2010 you can see how it outperforms USO when crude oil rallies, but as you can see it's definitely a trading vehicle because of the tremendous volatility (beta).

Chart is of UCO compared to USO August 24,2010 - February 8, 2011