HunterKiller's friends (variations) include:
ArchiveBot: mass collect all posts from all active threads in the catalogue (allowing you to do a raw text save of the data). Alternate version: bulk send archive requests of the thread URLs to archive.is/archive.org.
[Properly combined, you can keep a simultaneous offline/online version. Word of warning: when archiving to a website, be sure to only archive 'finished' threads on archive.is and to space out the requests over several minutes so it doesn't appear you are flooding/a bot. Automated and slow is better than manual and even slower.]
MonitorBot: keep track of which threads have 'moved position' and thus have 'new replies' (this is a technique used by shills to direct their limited resources to whichever thread is presently active; likewise, you can do the same).
KeywordBot: Have a bot that looks for specific keywords, image filenames or other triggers and then flag them up when it spots it (shills also use this technique to know when you're talking about a subject that they need to 'shill on').
Newsfeed/TrackerBot: use it to pull the latest news from websites (it's strongly recommended you use a news sites' RSS feed to do this as it keeps it nice and simple). Will require substantially more work and beware shitty unicode strings in the returned data.
Literally, whatever the hell else you could imagine. You're also not restricted to this board. If you change the URL to another board, the code should largely still work (albeit you might have to modify what data gets accepted as some boards don't have poster names).
If you want to get super anal, in theory you don't even need python to build an auto-parse tool. If you're batshit insane, you could even use wget coupled with a bash script.
Beautiful Soup and Mechanize are extremely powerful. Beautiful Soup does HTML parsing, and Mechanize is like a full-blown browser under the hood. You can post to a forum/board, but I've noticed the Media Matters shills appear to be doing everything manually (or whatever they have is absolutely shit), so I leave it as an exercise to talented chans to develop (highly advise you do NOT publish any posting capabilities as it will only arm the less well developed shills).
And believe me, this is just scraping the surface.