Script to grab a screenshot, put it in a Dropbox directory and copy its public link into the clipboard. Modified from: http://askubuntu.com/a/201018

byzanz-gui

#!/bin/bash

# AUTHOR:   (c) Rob W 2012, modified by MHC (http://askubuntu.com/users/81372/mhc), modified by Gabi (http://gabi.is) to use xrectsel and Dropbox
# NAME:     GIFRecord 0.1
# DESCRIPTION:  A script to record GIF screencasts.
# LICENSE:  GNU GPL v3 (http://www.gnu.org/licenses/gpl.html)
# DEPENDENCIES:   byzanz,gdialog,notify-send (install via sudo add-apt-repository ppa:fossfreedom/byzanz; sudo apt-get update && sudo apt-get install byzanz gdialog notify-osd beep)

# Time and date
TIME=$(date -u +"%Y-%m-%dT%H:%M:%SZ")

# Delay before starting
DELAY=3

# Standard screencast folder
FOLDER="$HOME/Dropbox/Public/screencasts"

# Default recording duration
DEFDUR=10

# Sound notification to let one know when recording is about to start (and ends)
beep() {
    paplay /usr/share/sounds/freedesktop/stereo/message-new-instant.oga &
}

# Custom recording duration as set by user
USERDUR=$(gdialog --title "Duration?" --inputbox "Please enter the screencast duration in seconds" 200 100 2>&1)

# Duration and output file
if [ $USERDUR -gt 0 ]; then
    D=$USERDUR
else
    D=$DEFDUR
fi

# xrectsel from https://github.com/lolilolicon/xrectsel
DIMENSION_ARGUMENTS=$(xrectsel "--x=%x --y=%y --width=%w --height=%h") || exit -1

# Notify the user of recording time and delay
notify-send "GIFRecorder" "Recording duration set to $D seconds. Recording will start in $DELAY seconds."

#Actual recording
sleep $DELAY
beep
byzanz-record -c --verbose --delay=0 --duration=$D $DIMENSION_ARGUMENTS "$FOLDER/GIFrecord-$TIME.gif"
beep

# Notify the user of end of recording.
notify-send "GIFRecorder" "Screencast saved to $FOLDER/GIFrecord_$TIME.gif"

# Copy Dropbox public URL into the clipboard
dropbox puburl "$FOLDER/GIFrecord-$TIME.gif" | xclip -selection c