Megathreads get around the problem of 73,000 threads on the same topic, but you still have the issue of the same questions coming up repeatedly because many people won't read threads over 20 pages. Maybe if we can prune some key threads to a few pages each and link to them we'll have better luck.
To be honest, search sucks and it's not readily apparent to Newbies that if you search from within a forum only that forum will be searched.
"Bitcoin Businesses and Developers, Let's Get Started!" -> whitelist requests
"Membergroups; or: Why do some users get colored coins under their names?" -> not bitcoin related, move to meta?
"Official Newbie BitInstant Support Thread (Active Customer Support)" -> private company that is currently having problems overselling BTC (and might end up with a hundred people scammed). why sticky?
Put Helpful articles for newcomers and terminology together.