As far as I know, if you don't remember the title, there is no way to find anything--and that only works if the article you want is in the first 30. As far as I know, there is absolutely no way to search for a keyword. And you can't even find much by going to google anymore.
All you have to do to set any keyword up is to click on the phrase "Click to Add Keyword" located at the end of the first post in every thread. It opens up a page with a little box, and you can enter any keyword or multiple keywords, as long as each one is no more than 20 characters in length. From that point on, you can, in theory, see all threads containing that keyword by opening the url "http://www.freerepublic.com/focus/news/keyword/whateverthekeywordis". But as you noted below, the software only returns the 20 most recent posts with said keyword.
As far as I know, if you don't remember the title, there is no way to find anything--and that only works if the article you want is in the first 30. As far as I know, there is absolutely no way to search for a keyword.
First 20, as far as keywords are concerned, but at least you can run said search as shown above.
You're right that the text of FR threads has never been searchable. And even searching on title words has been pretty hit-or-miss lately, for reasons unknown, so you often don't even get the most recent 20 or 30.
And you can't even find much by going to google anymore.
That's more a function of Google than of FR. Google chooses what pages to list depending on how many other pages link to that page. So if, for example, 30 different sites linked to that Columbia thread where we beat everyone in the news media by 11 minutes in reporting a problem with the shuttle, that thread will almost certainly be listed by Google. But the vast majority of FR threads, which never get linked to by anyone outside of FR, will never show up there.
However, there's nothing stopping FR from signing up for Google's Free SiteSearch feature, which would index most, if not all, FR threads. (Even better, FR could splurge for a Google Search Appliance and make up the cost during the next Freepathon. Well, maybe not; the cheapest Appliance is $28,000.) But there are all sorts of free and paid solutions Google offers that would allow us to conduct full-text searches on every thread ever posted.
By the way, as I understand it, the whole keyword thing was some rather detailed plan JohnRob had worked up, but for whatever reason, only the bare bones of it were ever programmed and implemented, which is why it doesn't really work.