My role in the team is a software tester (a software development engineer in test, we like to call it). There's a lot of hand-wringing in the industry and in Microsoft about what a software tester does. Lately, I've been leaning toward Bertrand Meyer's idea that software testing is about finding bugs (I paraphrase). So a software tester's basic job is to find bugs--that's what I do to varying levels of success.
To find bugs, we testers have to employ a large set of diverse skills. Programming skills to develop test cases, automation tools, test oracles, etc. People skills to work with our software development counterparts (not my core strength, haha). Debugging skills to analyze what has failed and how it failed. And intuitive skills--all testers at some point learn to listen to that sinking feeling in your stomach that when you turn a knob, everything will fall apart! I have to admit that sometimes, finding bugs in software is incredibly satisfying, particularly when you know that it ultimately isn't your job to fix it :P. Of course what's even more satisfying is that when we find the bug, we know that is one bug that people will not have to see when the software finally ships.
This being Microsoft, I work with some of the smartest, most dedicated group of people I have ever known (and I've known a lot of really smart people). That makes life exciting--everyone has valuable input, and everyone has productive output at a dizzying rate. Sometimes this can be difficult and exhausting, trying to keep up with everyone else, but it is also quite fun and challenging to learn something new every day. Perhaps part of what makes it enjoyable is that for a group of very intelligent opinionated people, this team is remarkably friction free (not entirely friction-free of course, no workplace is).
If you're curious to know more about the team I work with, a few of them have their own personal blogs: Joe, Igor, and Ed, plus the team blog. They talk about the hard-core meaning of life (or computer science which, really, is synonymous with life), while I post pictures of my dinner. :)