While the 460 might be a decent gaming card, ATI/AMD/Radeon cards are far superior from a mining standpoint. I'm not familiar with the tweaks using something like CUDAMiner (a miner specifically for Nvidia cards) might offer but you're never going to turn a profit thrashing that card for BTC because of power costs.
My Sapphire 7870 got to 410 Mhs with minimal tweaking, and I think 7970 cards are capable of 650 or so. Still not going to be even remotely worth mining BTC though after you factor in power costs and look at the ever rising difficulty. If you want to mine with your graphics card I'd recommend looking into an AMD card (or several!) and Scrypt mining (Litecoin, Dogecoin, etc) and then converting those into BTC. BTC minng has been an ASIC game for probably 8 months at this point.
The Bitminter client is awesome, easy to use, and recognizes a lot of ASIC devices. Its actually what I use, and if you end up with some ASIC hardware and keep mining BTC I'd recommend you stick with the pool. Dr H is really on top of things for us! Good luck
