In high school chemistry, my teacher told me that doing things with your non-dominant hand that you normally do with your dominant one creates new neuro-pathways. I have no idea if its true but I took it to heart and taught myself to write with my left hand. It came in really handy when my right hand cramped up in college classes.
I also use it when my brain can't put a sentence together. I've told you already that I write a huge proportion of my stuff in longhand first, right? Well, when I'm stuck, it helps sometimes to pass my pen, turn my notebook a little, and get something on the page. Its a little messier than my usual handwriting but it almost always gets me out of my head. Its how I fixed something today!
Its also fun. So the next time you're bored, or blocked, try writing with the other hand. And don't forget to tell me how it goes! :-)