[DirtyAndy]

I know a lot of "Web 2.0" sites are all look a bit the same, and I appreciate you going for a different look, but for me this doesn't work. If you look at other sites they tell you exactly what they are trying to sell in big letters, with clear screen shots on the front page.

Your video tells me little (well done though, that must have taken some time), three different sign-up options on the home page is messy, the link to screenshots down the bottom is just hyperlink, "Product Tour" needs to be at the top somewhere.

Do you really need a Captcha? I find them a pain in the arse, why not wait until you have a spam account problem.

As another commentator says, depending on your audience the Killer Startups and Best of the Web logos may actually devalue your product. If you are aiming for HNers etc definitely, however the general public seem to like these sorts of things sometimes.