This very old "plugin" from EdB might give a starting point, or at least be worth investigating....
http://forums.b2evolution.net/viewtopic.php?t=3315

One day I gotta upgrade that thing. Shouldn't be hard - just haven't had the motivation to get 'er done. Maybe right now would be a good time yah?

Hehe... yeah I guess today would be a perfect day (rain outside, no work to do, friends/girls are out of town...)!

; )

Funny thing happened ...

I worked on it, figure this might do, uploaded it, added a keyword, made a post with the keyword, it linked, but my skin was totally bonked even though it was supposed to be good old 'custom'. So I unzipped the package again and got a "clean" version of custom, reset the database on my test installation, re-uploaded the 'custom' skin, and now it won't render the keyword in a new sample post.

Ha ha - isn't that the funniest thing you ever heard?

So progress is finally happening. It will have the same "do acronyms or do auto-links" option, and the options I had for who gets to add and edit keywords, and an option for case-insensitivity. I think I've also seen the way to make it (optionally of course - I *love* optional settings) do "render each word only once per post" or "render each keyword each time it shows up in a post".

This will be my thing for a little while today as I do my laundry so I can attend another one of those stupid things where you go somewhere for 12 hours and do stupid stuff so someone will give you money. Anyway now that it's on my mind it won't get off it until it is a respectably publishable package.

I'm glad to hear that ! Let me know when you'll be done with it.