It depends on what you do, but if you're a freelancer, finding your own clients, managing your own projects, and paying for your own social security and benefits, then 100/hr is fair for a good programmer in NYC. It is comparable to 100K full-time, full-benefit work, which is at around what one of USV's NYC portfolio companies will offer you if you're a good programmer w/ 6 years experience.

If you feel you are underpaid, then apply for one of those positions on USV's portfolio jobs page. All of their NYC companies are awesome.