I'll add one more:<p>* Can you support Twitter OAuth, or FB Connect, OpenID, clickpass .. ?<p>We're all tired of signing up for yet another site. Usually if it's a rather prominent site whose value I already understand and I know the value will be useful to me, I don't mind biting the bullet and registering. I forget where I read this, but there was this speaker once who said "Customers don't just pay with money. They pay with their time and angst" (paraphrased).<p>For more obscure sites I don't want to register because I don't know what they'll do with my email address, plus mentally I am trying to figure out if my annoyance of having to sign up for yet another site is going to actually pay dividends back to me at all. I don't want to waste my time.<p>Basically the registration part is barrier to entry for me, and I think it will help if you remove that friction from the sign up process.<p>Kind of like <a href="http://CofounderGoogleDocs.com" rel="nofollow">http://CofounderGoogleDocs.com</a> - the Google Docs spreadsheet for co-founders I posted here on HN recently. Many people jumped in because there was no friction. You just go to the page, and start adding your info (or start grabbing info)