Jeff Key does it again...Pixel Ruler for Windows
He's prolific. You're likely using his tools today, and you may not know his name. He's D.J. Jeff Freakin' Key baby, and he's done it again.
Check out his new Screen Ruler. Ya, I know it's been done before by others, but his is in .NET, and it's transparent.
Additionally, if you're not rockin' Snippet Compiler, you're a punk. And I don't mean that in the nice Modern English way. Check out his library of goodness here.
One of the things that I have to give Jeff props on (take a note here, non-UI developers) - his stuff is ALWAYS polished. It's consistant and it's pretty. Not pretty in an overt way, but in a "fits into your life way." The only other developer that has impressed me with their consistant and clean UI is Nick Bradbury.
Note to Freeware/Shareware authors. I will ALWAYS pick the cool transparent app over the opaque one. Maybe that's just me.
(Additionally you have to respect a guy who uses PNG. Also, you can pick Jeff up on ebay cheap.)