I found this really cool and really convenient way to do screen caps.
You can give it a try at: Screen Toaster
I highly recommend it and since its browser-based, its compatible with Macs, PCs and even Linux.
This paint sketch was a result of my little test run. I'll post the vid as soon as I finish the clean up and edit.
UPDATE: Here is the video for the above paint sketch using Screen Toaster to record.