If you really don't want to see your CPU wasted while you mine BTC on your GPU, have you thought about mining LTC on the CPU? It would actually be way more profitable than trying to mine BTC.
Have not researched it much, I don't even know the difference with bitcoin/litecoin/namecoin, I just know bitcoin
But doesn't a GPU produce Litecoins at the same greater ratio over CPU that it does for bitcoin?
Actually, no, it's quite the opposite. The scaling from CPU -> GPU is MUCH lower for LTC. GPU miners are 100x faster than CPU miners for BTC, but are only 5-10x faster for LTC. It was my understanding that it was designed for such a purpose - mine BTC on your GPU, and LTC on your CPU.
Do you know what Khash a G530 could get in Litecoin hashing?