If the person you seek has registered with the service, you can send them a quick personal message via your cell phone. The respondent then receives the message via their cell or email address. At no time are any contact details available to either user. Currently the service is free and has over 2 million members registered.
Another handy use would be to swear at the
idiot person who cut you off in the morning.
Edit: You'll notice that the related post to this article is a link to the Contact Us page. Just to clarify, we're not cute girls. We're more likely to be the guys that cut you off in the morning.