I tried to switch my 7950 card to litecoin mining - wasn't really worth it, really disappointing hashrates compared to the power consumption. I'm back to mining bitcoins for now, while that's still marginally profitable. Mining litecoins, I'm getting nearly the same hashrate using the spare CPU cycles of three rented root servers (i.e. I don't pay extra for electricity) that I was getting with my 7950.