I purchased myself a dry erase board yesterday. I find it's a great way to sketch out quick ideas for my story or for drawing things like menu items at a café. Unfortunately it's not permanent so anything you want to keep has to be copied over to something. But still it does help me to "Think Temporary" and serves as a bit of a "Buffer Space" for ideas. It's nice in developing an idea for your story because you can erase things and put in something else extremely easily.