We currently accept bitcoin and litecoin as those are the two most popular crypto-currencies. As other currencies become more popular we definitely plan on adding those to our accepted currencies which you may use to deposit and withdraw from.
Fortunately, it is very easy to exchange between crypto-currencies using many of the fine exchanges out there. In most cases you can exchange from one currency to another in a matter of seconds. Please try www.btc-e.com if you need to convert between different crypto-currencies.