I've been running a litecoin miner for a couple of days now, its really not very effective on my laptop (getting about 40khash/s) which translates to about 0.5 litecoins for 3 days.
I don't pay for power though so who cares
It works a lot better on AMD stuff, but if your nVidia use Cudaminer.
If i leave it going i might even get 1 litecoin by the end of next week, worth about £15 atm, but could explode like bitcoin...