While I'm yet a young programmer, the primary paid experiences/internships/jobs I've had with programming have been in the biomedical/bioinformatics field. My first day on the job? Did probably all the work they'd expected of me the entire summer (all using a simple "programming" trick with Excel) then proceeded to write them a few program to make their data-entry/processing jobs a lot easier and more precise. I was like a magician.

It was pretty cool.

I've had nowhere near as much experience as Zed or many of the people replying on here, but my experience in different labs and situations has been similar.

On another related note; I was talking with an international finance/investment profession when I expressed my dual interests in finance and neuroscience. She immediately made the point that I'd be infinitely more valuable in finance with a hard science background (particularly in financing the field my background was in).

Moral: Domain knowledge and niche/cross-discipline expertise is valuable.