I’ve been a big proponent of Jing for screencapture for a while. I still love it, and it’s top notch for sharing video, but I’ve come to enjoy a free tool called Gyazo for screenshots. Both of these tools are invaluable when it comes to web development QA.
Below you’ll see a screencast demonstrating gyazo to the #jquery IRC channel:
Both Jing and Gyazo provide hosting for you (infinite, eternal store, as far as I’ve seen), and they both automatically copy the url to your clipboard. Gyazo is a bit quicker for images, and also doesn’t have a business model, which is comforting. :)
And it’s cross-browser as long as you don’t mind some Japanese text:
Oh and open source. :) I think you can even host your own image repo if you don’t want to use gyazo.com.
Handy tip, keep the shortcut somewhere totally handy. On Windows, I keep mine with the quick launch icons.