Correct me if I am wrong, but both Google and Microsoft were founded by drop-out students. If they had actually finished, then there average age would have been higher. I am 28 now after finishing undergrad, grad school and working in the biotech industry for 2 years, and my start-up drive is higher than ever. I think age is irrelevent if you have the drive, commitment and maturity to succeed.

However, I do have the problem of finding like minded individuals at my age that are willing to take the risk of joining a start-up becuase they are used to the comforts of having a "secure" job. They tend to see doing a start-up as a bit of hobby, but this doesn't bother - I wouldn't want them to work with me anyway because I expect the same commitment to the project as I have.

Anyway, at 28, I am still going to apply for YC. Power to the old giffers!