Strange, I just tried to register as as new user and the only options were for username, password, and birthday. I think b-day is mandatory for legal reasons around online child protection laws.

It asked for gender and location on the second page of the registration. Now that I look at it again, it's not mandatory; but that's not very obvious.

Anyways, cool idea, it's just a shame that Ning's signup process is so convoluted.