I did that, which was fantastic experience (good coworkers, nice codebase to work with and an interesting industry) and led to me being employed by the same company upon leaving University. While interviewing for my next job, it was often mentioned that I had 18 months more experience than others in my position (recent-ish graduate), and they valued that much more highly than they would one additional year of in-University education.
As for getting a job without a educational backing, it's all about proving yourself. I have a friend who's co-worker had never been formally educated, but was a senior developer at the firm. He had a solid portfolio and ran his own small web development effort on the side. Code things, and show them to prospective employers.