Need a quick drawing tool?

I use Visio a lot at the office, but at times I need to do a quick diagram — either of a floor plan, or a flowchart, or even a network – when I’m out of the office or don’t have my laptop with me.

Recently I stumbled across Gliffy, which is a free web app for doing drawings. It includes version history, and allows you to let other users share and collaborate on your drawing. Here’s a sample of what it can do: