How can you say it's only used by Americans?
The OP is English, and he uses it, as I'm sure many other younger English people do. I admit it comes from an American influence, but hey ho, languages are constantly changing. If they didn't everyone would still be saying gotten instead of got.

English is changing at a very fast rate indeed at the moment, both grammatically and semantically. Just look at the new trend of using stative verbs with the continuous aspect and the noun verb shift in business English. The driving factor at the moment is American English, but don't worry, I'm sure the emerging global dialect will take up the baton soon. You may like that even less though, I give third person singular conjugation of verbs, and the perfect aspect fifty years at best.
( The Awful Puppy Bakery is still bored, Sun 6 Feb 2011, 0:07, 2 replies)

So by the same token
will you accept txt spk as perfectly acceptable written English?

It might be what young people choose to use, but that doesn't stop it grating.
( Mrs Entity is in hiding., Sun 6 Feb 2011, 0:11, closed)

Don't get me wrong.
I hate it when I hear British people saying gotten, it doesn't change the fact it's making a comeback.

As for text speak as written English, you'd be surprised- or maybe not- how many of my students do exactly that. It's getting to the point where I can't always be bothered to make them change it.
( The Awful Puppy Bakery is still bored, Sun 6 Feb 2011, 0:19, closed)

Aargh!
I absolutely hate that! I blame bloody McDonald's - "I'm loving it." Excuse me while I go and break something...
( SteamedCleaner, Sun 6 Feb 2011, 4:22, closed)