I can't take full credit for this mod, its mainly a hack of an largely unknown client mod called picbox. I've improved it and made it work for Kraftzone. My original idea for this mod was that it would allow a user to select there own image upload site or provide ftp details for the mod to upload too. However since finding someone already had done this mod, I've just done the easy thing and change it up a bit, and also no need to make an account.
Changes include using jpg format, and preset quality control instead of .png, by default minecraft saves screenshots as .png which are very high quality lossless, however the size per screenshot is pretty high and when uploading that, its just not as fast as a jpg at high quality.
I might offer some other versions of the mod with varying jpg quality, or the full .png support again, but for now this is testing.
Install the mod like most other minecraft mods, ie delete META-INF chuck extracted .zip files into the minecraft.jar ..or use mcpatcher on the mod .zip (my prefered method)
Go in game and press F2 (this will save a screenshot as normal), it will also say "Uploading screenshot..." (depend on your upload speed) you will then get a url sent back to you for you to use to look at and share like on this forum
VERY FAST, none of this bullshit finding your taken screenshot in the minecraft screenshot folder converting to jpg and finding some crappy image upload site
You can see why I wanted this mod now