Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.

Img.vision - Image hosting & video hosting for eCommerce sellers

Capture2text - Capture2Text enables users to quickly OCR a portion of the screen using a keyboard shortcut.

BeeIMG - BeeIMG is a simple, fast, easy image sharing solution created to fill up your image sharing needs.

ksnip - Ksnip is a Qt based cross-platform screenshot tool that provides many annotation features for your screenshots. - DamirPorobic/ksnip

ImageVenue - ImageVenue is a great online hosting service that allows uploading pictures for showing creative works with a simple-to-use technique.