On a trip to the cinema last night, a housemate mentioned "My phone knows Matrix but not Reloaded". Adding the word to the dictionary solved the problem, but I doubt he's the only person who's needed that word in the last week. So why not share SMS dictionaries around the network? New words would be reported to some central point, and any that more than a couple of people had needed would be automatically pushed out to all the phones in a nightly update.