Kathy Sierra has a great post called Do Something Scary.  She quotes Eleanor Roosevelt who said “Do one thing every day that scares you”, and continues talking about trying new things (taking risks) and expanding your experiences.  This is something I’ve been trying to do for the last few weeks, and have had a few minor successes (at least in my book), so I’m going to keep tacking new risks, try new things.
The post is a really good read, you should also check out Death by risk-aversion, another post by Kathy.