Here's an idea to try -- Scrabble played with Google as the base, rather than the dictionary. Ie. you can play any word you can find in Google (sort of.)

This obviously vastly expands the set of words, perhaps too vastly, and it brings in all foreign languages to boot. It includes vast numbers of joinedwords, and zillions of other things. As such you would want to consider the following limits:

• Only words from Google 5 or more letters in length count. Just about everything of 3 or 4 letters is a domain name now.
• Typos and misspellings don't count. If Google suggests an alternate and you don't have something else to back it up as real, it's not usable.
• Or more simply, require a minimum number of hits, like 1,000.
• Make the rules for missing harsh. If your word is not in Google, you lose a turn, lose tiles, lose points etc.
• Since there are not any numeric tiles, no 1337-speak. But you can get PWNAGE over other players.

Let me know if you try it.