There's one making the rounds in Christian circles called something like "How to Forgive when you can't forget". The main take-away most readers i know have had is that forgiveness doesn't equal reconciliation. You can let go of the pain or the anger or whatever you feel for how they treated you, and move on without the burden of unforgiveness, without letting them back into your life.
I'm no Christian, but that's pretty much where I am.