What's a good (preferably free) on-screen ruler for Windows? (Vista, if it matters.) I just need to measure a few things (in pixels) on the screen. I need it to be flexible (easily resizable and able to measure both vertically and horizontally), and hopefully not look like crap, although I can deal with that if it does what I need. A quick Google search revealed a ton of different applications, and I don't want to try every single one.