Blaxx,
I would assume your using the USB version and not the XLR? If so you will need to adjust your gain through the sound manager in windows and move the mic closer to your voice hole.
a quick google search showed a lot of hits of other people experiencing the same problem. Mechanical keyboards dont help either.
My .02 on it, the blue yeti is over hyped and over priced, I went for the Zoom H4N and pocketed the rest of the cash and couldn't be happier.
EDIT: check out this message board, lots of good advice to help eliminate your problems
http://recording.org/threads/best-way-to-eliminate-background-noise.50322/
