Here’s are two scripts to do what GrabBox does on OS X – they take screenshots and then place each in your public dropbox folder (edit the url to fit your id where xxxxxxx is). The first script snap.sh does a full screenshot. The second lets you click on a window, and that window will be grabbed. I set up some fluxbox key bindings to call these scripts. The url will be injected into your clipboard using xclip for quick paste in an email or in IRC :-)
snap.sh:
#!/bin/bash
RAND=`cat /dev/urandom| tr -dc 'a-zA-Z0-9' | fold -w 24 | head -n 1`
IMAGE=${RAND}.png
scrot -d 0 -q 10 ~/$IMAGE
cp ~/$IMAGE ~/Dropbox/Public/Screenshots/${IMAGE}
echo "http://dl.dropbox.com/u/xxxxxxxx/Screenshots/${IMAGE}" | xclip
rm -f ~/$IMAGE
#http://dl.dropbox.com/u/xxxxxxx/Screenshots/2vaq%7Exr5lr6x.png
snap2.sh:
#!/bin/bash
RAND=`cat /dev/urandom| tr -dc 'a-zA-Z0-9' | fold -w 24 | head -n 1`
IMAGE=${RAND}.png
scrot -d 0 -b -s -q 10 ~/$IMAGE
cp ~/$IMAGE ~/Dropbox/Public/Screenshots/${IMAGE}
echo "http://dl.dropbox.com/u/xxxxxxx/Screenshots/${IMAGE}" | xclip
rm -f ~/$IMAGE