I believe in both. They need not be mutually exclusive.
Since neither can be totally proven beyond a doubt (one is based upon scientific research principles but remains a theory, and the other on a book written by men long after other ideologies existed (so, relatively recently) that men said was dictated by G-d and was translated who knows how many times into thousands of different languages (understand that translations are never exact, so when you have multiple translations, you'll have multiple interpretations)), it just boils down to deciding what feels right to one's self (for instance, it feels right to me that G-d - as a spritual entity, not as a conscious individual - created the universe of which evolution is a part).
In the end, one's belief of evolution vs. creationism is not really going to have any bearing on what you're going to have for dinner tonight, although other beliefs may (that means that it's basically a moot argument and good more for personal speculation and lively debate than an actual definitive answer).
What a fun and fascinating question!