Take a snapshot with iSight and upload it to twitter as you profile picture

twitter_pic

#!/bin/sh
#
# download isightcapture at link below
# http://www.intergalactic.de/pages/iSight_files/isightcapture1_1.dmg

isightcapture -t png /tmp/capture.png
curl -u user:pass -H 'Expect:' -F image=@'/tmp/capture.png;type=image/png' http://api.twitter.com/1/account/update_profile_image.xml > /dev/null
echo "Profile Pic Updated"

twitter_pic_scpt

#!/bin/sh
#
# Use this version when running as a cron job.  First make an applescript to capture snapshot.
# Paste the following line in a new AppleScript file 
# 
# do shell script "/path/to/isightcapture -t png /tmp/capture.png"
#
# then save as application to /Applications/Snapshot
#
# download isightcapture at link below
# http://www.intergalactic.de/pages/iSight_files/isightcapture1_1.dmg

open -gW /Applications/Snapshot.app
curl -u user:pass -H 'Expect:' -F image=@'/tmp/capture.png;type=image/png' http://api.twitter.com/1/account/update_profile_image.xml > /dev/null
echo "Profile Pic Updated"