You can now buy and short litecoin as well as bitcoin on
http://www.plus500.com/?id=69295&pl=1 - ref link
plus500.com - non ref
Note you're not actually dealing with bitcoin or litecoin. This is trading CFD's so if you were to purchase 10,000 bitcoin, you wouldn't alter the bitcoin price. I myself made a few bob by shorting bitcoin when gox froze on the recent crash.
A CFD, or Contract for Difference, is an agreement between two parties to exchange the difference between the opening price and closing price of a contract.
CFDs are derivatives products that allow you to trade on live market price movements without actually owning the underlying instrument on which your contract is based.
You can use CFDs to speculate on the future movement of market prices regardless of whether the underlying markets are rising or falling. You can go short (sell), allowing you to profit from falling prices, or hedge your portfolio to offset any potential loss in value of your physical investments. Moreover, with over 10,000 markets to trade, you can gain exposure to markets you may not have had access to before. We offer prices on shares, indices, currencies, commodities and more. See an example of how you can trade CFDs with City Index.