About a fortnight ago a new friend of mine introduced me to this ingenious little tool which has became invaluable to me for producing quick and easy screenshots. It's a program called Puush. It's an amazing little thing which allows you to instantly take a screenshot and get it hosted, then automatically copying the URL to your clip board for pasting. It can even be used to create a live "crop" of your screen, so you don't need to edit sizes of your pictures if you're trying to highlight a certain aspect. I have been told it does have some problems when it comes to taking snapshots of some games in fullscreen mode, but then I think most the people I know who play here use a window so that won't be an issue. The keybindings for controlling puush are customizable too so that always helps, but here's the default set anyway.
Enjoy!