I haven't really given a plug to Twitter before and I believe this service is a one of a kind.
What is twitter?
Twitter is a free social networking and micro-blogging service that allows users to send "updates" (or "tweets"; text-based posts, up to 140 characters long) to the Twitter website, via short message service (e.g. on a cell phone), instant messaging, or a third-party application such as Twitterrific or Facebook.
Updates are displayed on the user's profile page and instantly delivered to other users who have signed up to receive them. The sender can restrict delivery to those in his or her circle of friends (delivery to everyone is the default). Users can receive updates via the Twitter website, instant messaging, SMS, RSS, email or through an application.
How I benefit?
Only just yesterday I solved a query of mine by posting a message out to all my followers about whether they recognize a font a client needs that they have used before in their branding. About an hour later I had my query answered.
This has happened many times before where I've had the most complex question answered by someone who is well experienced in the area. But before you can get people to answer these questions you must have a connection with them (ie: they have to follow you).
Your messages 'can' appear on the public timeline but the chances of someone picking up on your message is very unlikely. So jump onto Twitter and follow people you're interested in, reply to their messages and before you know it you'll have some connections.
Message to twitter: "We'd like to thank you in 140 characters or less. And we just did!"
Don't forget to follow me!