I subscribe to myFICO, a credit monitoring service. I have it for two main reasons: 1) keeping an eye on my credit report, and 2) bumpage. As it turns out, I recently discovered that Equifax showed a large balance on my report for a Discover card. This concerned me, because I don't have a Discover card. I called Discover, and it's an error.
myFICO (almost) automatically drafted a dispute letter to Equifax, which also let me update some other minor errors on my report, as well as my employer information.
The bumpage is nice too, because I've had several inquiries lately from switching to ATT for my cellphone, and U-Verse for my TV package. This will help get rid of those inquires faster.