Journaling is very good for the mind. I have a lot of random thoughts and theories about business, life, politics, science,etc that I love to document. Writing it down forces you to think out my ideas into something coherent.It's fun to look back in your jounal and see what you were right or wrong about. And for some reason it is an emotional release.

I use a livescribe pen to jounal. Stores everything I write down digitally.