FFT software

I am looking for VB software to do FFT.
I want to get from the MIC input on the s/blaster card and show audio frequency spectrum, preferably with adjustable frequency filtering.
Most of the commercial programs have too many buttons
more my end-users.
Anyone can help?

I had to use FFT's too, this place has a pretty good FFT

http://www.fullspectrum.com/deeth/