I was just reading a Techcrunch blog post on the the local services market Workstir.com.
I went and signed up to be notified for the private beta.
Then after I signed up it gave me the following option on the thank you page:
In the meantime, if you could help us out by tweeting about Workstir, that would be amazing!
It gave me a twitter login, then took me to the twitter site.
Pretty smooth move, I just helped them in their social media marketing.