Well, I know this is only going to apply to a small amount of people, but I made a danbooru upload script for *nix systems. The FF extension is okay, but I didn't like browsing my hard drive with a browser. So if you have Linux or a Mac, this script will upload a batch of similar pictures for you to the Channel with one command. This might work with Windows/Cygwin tho.
http://pastie.org/431771
and save as ~/bin/danbooru-upload and set chmod +x
To start, create the config file at ~/.danbooru/danbooru-upload and populate it with
[sc]
baseurl=http://chan.sankakucomplex.com
Login with
danbooru-upload -l sc
and upload like this
danbooru-upload -n sc -t "touhou tatara_kogasa" -r questionable -f "$HOME/Pictures/kogasa/*jpg $HOME/Pictures/kogasa/*png"
which basically does "upload to the channel all my kogasa jpgs and pngs with the tags 'touhou' and 'tatara_kogasa' and rate them questionable."
Or you can use within another script and source a doujin to a pool.
for page in $(seq -w 03 23); do
danbooru-upload -n sc -p XX -t "beako doujinshi" -f "hxxp://torot.net/main/comic/backbeard/napo/bea_n00$page.gif"
done
check help and options and example commands with
danbooru-upload -h
Despite the number of options, the script is kinda limited, but I think it is good enough to push out similar pictures. But it's not meant for truly random image sets. Of course, I made it with how I would like to upload pictures, but if anyone wants their way added in, I'll try to implement it. Edits, GUIs welcome too.

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