One option you have is to look at portfolio companies for the major VC's to see if they are looking for developers and are tackling problems that are interesting to you. Some examples:

http://jobs.sequoiacap.com/ http://www.usvp.com/ http://jobs.kpcb.com/

This would get your foot in the door of the "world of start-ups" without taking the plunge of doing your own thing.