I record at 24-Bit, 96Khz.
Why because I can...lol.
I have a powerful PC, and a terrabyte of hard drive space. I can't hear any difference, but it doesn't make my machine run noticeably different recording in this format either. Due to my (admittedly shaky) understanding of the Nyquist effect which states something to the effect of "unambiguous reconstruction is possible if the signal is bandlimited and the sampling frequency is greater than twice the signal bandwidth", there seemed to be at least a possibility that recording at higher than 48Khz might have some benefit.
Peace!
amra