Comment followup: Lightshot lets you quickly take and share screenshots
If your mind is reeling with the recent wealth of screenshot-related tools that I've started posting, don't worry; I will soon be writing a comprehensive roundup pitting them all against each other.
Lightshot sets itself apart with two main features. The first is a slick-looking overlay menu that lets you choose what you want to do once you've taken a screenshot. One of the options instantly uploads the image to a domain with a really catchy name: prntscr.com. Your image gets a short URL; my image got http://prntscr.com/goic. Interestingly, prntscr.com seems to be just a simple tie-in to ImageShack. When you click the image on prntscr.com, you go to a regular ImageShack page.
The other interesting feature that Lightshot offers is online editing using Pixlr. It's a fairly powerful Flash-based editor, but it ties into Lightshot quite awkwardly. Lightshot loads the image onto the prntscr.com domain then fires up Pixlr with your image in it, but once you're done editing, you can't save back onto that same location!
You can either save the image locally (in that case, why did you bother uploading it in the first place?) or save it to Pixlr's own image-sharing server (imm.io). Now, two copies of your image are floating around the Web; one of them is edited, and one of them is raw. Needless to say, once your image is in the cloud, it's not really going anywhere (as is the case with most of these tools). If you've uploaded a screenshot of your Social Security number by mistake, that's too bad.