Expanding on an idea originally posted on the Freakonomics blog, Andrew Lynch suggests soliciting people you admire or respect for an unpaid internship:
Find someone you really admire or respect. Email them. Describe your skills, how you can help them, what you have to offer. Link them to your blog full of quality posts. Then offer to work for them for free. If they accept, take whatever task they give you and knock it out of the park. Go the extra mile. Make it your most important task for the day, or week, or month. Do the work quickly and efficiently. Then, when you’re done, email the person and say that it was a pleasure working for them, and you’d love to help them out in the future if they have any other cool projects lined up.
Pretty good advice for both students and those seeking a gradual career change.