* Delete them from your facebook friends and block them. You don't want to know what someone's up to when you're trying to get over them. Delete or restrict their friends on your profile too. No news about an ex is good news as it helps you to fade them from your thoughts.
* Delete all of their numbers and email addresses from your phone and computer. Just so your not temped to contact them at some weak point.
* Call up those single friends you haven't been in touch with lately and organise to catch up with them. Make plans to visit relatives to catch up too.
* If the weather's nice - get out in the sunshine, have a dip in the ocean, or go for a run - It's amazing how good it will make you feel, and how peaceful it is.
* Take up that leisure class you've always wanted to do - Salsa, Tennis, etc.
* Take a mini-holiday - Just a night away somewhere you can drive to with your close friends will do.
* Get yourself a new haircut, or new dress.
* Have a big night out dancing.
* When your at home alone do something to occupy your mind, craft, painting, reorganising your wardrobe, anything that doesn't allow you time to sit around moping.
Hope these ideas help, best wishes for a new start in 2012!