I have been finding Skitch very useful these days.
Brian Caldwell first introduced it to me months ago, but I never thought I would want to save all my screen grabs as much as I do today. Working on the web 10 hours a day, something will catch you eye, and you don’t really have time to take a screenshot, convert the PNG to GIF, and upload the picture. Skitch makes it so easy.
You should check it out. My Skitch page is quickly becoming my “screenshot blog”. It’s also really easy to share Skitched images. You can set privacy settings on each image you capture.
Plasq Inc. also makes cool products like Comic Life and Doozla.