+1 to systems work. I was a programmer, then a manager, then an Oracle dba (each for 4-8 years). working with databases is by far the most rewarding and challenging, and I still get to code tons of useful tools.
Grandparent got deleted, but it suggested that you may be interested in systems administration.
I was also a Math geek, and hadn't programmed a lick until sophomore year of college. I graduated with a CS degree. Programming was interesting, but I much more enjoyed the hardware aspect, so I went to IT. I'm different than my sysadmin coworkers because I can read source code, write decent chunks of code, use databases, etc. The CS background can be very helpful in figuring out why something works like it does, and then you can start optimizing from both sides (writing better software for the hardware, and fitting the right hardware to the software).
