(re: Legality of Fan AGI/SCI games) Ok, I checked the links to the sites I mentioned.Search here for trademarks:
I just did a basic search for Sierra On-Line (as owner) and came up with 220 hits.
The copyright archives can be searched here:
A search for Sierra On-Line here got me 163 hits. Check out the details of the records for fun additional info.
BTW: Ken, when you registered a game copyright, would you do it before development started or just sometime before the game was publicly announced?