Twitter is a useful and very popular social networking tool. You can make a tweet about anything you like (144 characters or less anyway), but just like with Facebook you need to self-monitor your tweets and keep certain thoughts private. ESPECIALLY if you are or have just graduated from high school or college and are looking for employment. Most employers will do an internet check on a potential employee...so don't leave any harmful pictures or posts out in the world wide web that could come back to haunt you.
This blog posting from Mental Floss talks about how to tweet yourself out of a job.
-