Topic: Quick and dirty schema sketching
I just discovered this and thought I'd share it. If you use Chrome, there's a free app called Sea Quail that lets you quickly and easily sketch up db schemas.
You can find it by going to the Chrome Web Store, then do a search for "Sea Quail".
It's a bit glitchy, and lacks some needed functionality, but I think it's great for getting a quick and dirty db schema sketched out.