Club Penguin. It was a Web 2.0/virtual community play. Acquired by Disney for $350+ mil. I don't know if Plentyoffish qualifies as a Web 2.0 startup, but it is making a lot of cash. I could name a few more. Cheers.

PS. I agree with the original poster "The first mistake startups make is they need VC or angel funding to get moving," if by "get moving" s/he means get started. You might need it when you want to expand, grow, get serious, etc. but you don't necessarily need it at the beginning.