To learn Ruby, I wrote a script to make command-line uploads easier. It currently supports S3 (including torrent and authenticated expiring URLs), Cloudapp, and Imgur (for images). You can check it out here:
Why use a custom python script when you can just copy the screenshot into your dropbox folder? Ok, I guess it's for when you don't use the nautilus extension and don't link your filesystem with DB...
Would be cool if you could change the output location of compiz' "windows key + mouse rectangle produces screen shot" add on.
https://gist.github.com/1683661
You need scrot, xclip, and libnotify. Set up private key ssh access to your webserver and update the directories/url and you're good to go.