I've recently been looking into bioinformatics and computational biology because I love the idea of manipulating biology or biological information with computer science. I believe the ubiquitous integration of technology into human physiology is an inevitable leap that will be undergone in my lifetime. We have already laid the groundwork for this revolution and can do things like control rats' movements with joysticks, rewire part of the body to bypass damaged nerves, and crossbreed goats with spiders to produce significant amounts of spidersilk. Who says we can't port wifi drivers and emacs into the human cognition system??
Anyway, a quick wikipedia search of bioinformatics lists an incredible set of interesting topics including modeling biological systems, comparative genomics, analysis of mutations in cancer, measuring biodiversity, computational evolutionary biology, and DNA sequence analysis. You probably aren't as excited about these topics as I am, but it is terrific to see this huge variety of cool problems fall under a set of highly interconnected fields, all of which impact humans globally on a day-to-day scale (mostly through medicine). Fun problem solving made relevant! I'm definitely ready for a break from school, but damn, who wouldn't want do research computational evolutionary biology for a few years?