Most people don't need motivation, they need a working system for getting things done. I just started using the "getting things done" system and it works surprisingly well.
http://www.amazon.com/Getting-Things...30790&sr= 8-1
I've also been using OmniFocus (Mac) with great success.
http://www.omnigroup.com/applications/omnifocus/
There are also quite a few getting things done (GTD) programs for Windows out there. If you're having trouble staying focused and getting things done, I would suggest you try the GTD system. I used to blame my lack of motivation on everything from caffeine to ADD. As it turned out, all I needed was a better way of organizing all my tasks.