Gyazo is available on Mac/Windows/Linux
Here is what makes Gyazo so convenient:
Click to capture your screen and release to instantly upload the image. The link to the image page is copied to your clipboard automatically. You can share anything on screen right away.
Simply paste the link into chat, facebook, twitter, tumblr, or anywhere else you want. Share screenshots with a small team or a big social network, across all connected devices.
You can now also capture animated GIFs easily and instantly. Simply click the new GIF icon to record a section of the screen for up to 7 seconds.