I just learned about an application called Puush. (http://puush.me)
Once you have an account, CTRL+SHFT+2 or +3 or +4 lets you grab a screen capture and saves it to your account and a URL to your Clipboard at the same time. And you can then post it.
After a month, the pictures go away if not visited. Every time they are visited, the are refreshed.
A great way to capture a tweet or silly chat message, that you aren't needing to save permanently.
Although, you could also go through your account and save the picture locally before it expires.
Super simple.
I highly recommend it.
(http://puu.sh/6suLu.jpg)
I use puush since ages as you can see by most images i posted.
Its not just for images. I use it for flash and even dokuments. Just a quick way to share stuff.
(http://puu.sh/6sFTJ.png)
I find upload from clipboard most useful.
Also, uploads last way longer than on other sides i feel. And you get alot of space for your uploads.