iMONITOR
Silent Key
64bit is faster loading than 32bit, plus allows for more than 3(4?) MB of memory.
I don't know about faster loading, but I'll agree with 64 bit overcoming the memory limitation. However, I've never been able to get Windows to use more than 1.5GB of RAM no mater what I was running, or doing, with multiple applications, etc. So the 4GB ceiling has not been a problem at all.
There are very few 64 bit applications. So when you run your 32 bit applications on a 64 bit operating system, they're all running within a 32 bit emulator, which means more OS overhead, and loss of performance.
What really cracks me up is Microsoft is already talking about Windows 8, and 9, and 128 bits. I think they're getting ahead of everything else, with no real benifit.