The truth is, I went into Mathematics because I was good at it and I loved it. I especially loved the "pure" kind of mathematics, and to this day, I'm involved with GIMPS, the search for Marsenne prime numbers. And while prime numbers have applications today in modern cryptography, it's basically pure math. Likewise, topology (geometry on a non-flat plane) always intrigued me most of all.
But the truth is, as I've discovered, a Mathematics degree is a stepping stone to graduate school.
What I'm saying is, don't listen to the people that tell you an undergrad degree in Mathematics is useless. Good math skills are useful wherever you go. Who do you think designs IQ tests, eh? Psych PhDs with skills that are better than the average bear, that's who!
And if you've got a lower division mathematics degree, try going into physics or engineering. The problem with the mathematics used by those two groups is, their use of math is extremely heuristic. Math, to them, is almost magical, like a kind of voodoo. A math background gives you the ability to actually reason and work with numbers.
If you're in the process of getting your mathematics degree, try to concentrate on linear algebra, as it is at the heart of ordinary and partial differential equations. Don't forget numerical analysis and linear programming (as well as optimization theory) as that may be helpful to a computer-centered field.