I'd recommend reversing the workflow like http://min.us.
Accept the content first, then authenticate when users try & save. It removes a barrier to entry, and for people just testing, doesn't waste subdomains.
I'd also recommend ditching the subomain for a subdir. Regular people don't really get it. Yes, there are major services that do it, but i know from experience that social networking has trained average folks for years to use subdirs vs subdomains (twitter, facebook, myspace).
Accept the content first, then authenticate when users try & save. It removes a barrier to entry, and for people just testing, doesn't waste subdomains.
I'd also recommend ditching the subomain for a subdir. Regular people don't really get it. Yes, there are major services that do it, but i know from experience that social networking has trained average folks for years to use subdirs vs subdomains (twitter, facebook, myspace).