Please tell me you sent 'd' back.
It's a message from an IM client sent to your SMS? Hmm...
they work me and my friend talk like that. Im on a iPhone texting and him on his pc.
If i was you, I would dial "611" (AT&T Customer Support) on my iPhone and report the text to AT&T. They will investigate it. I reported a telemarketer to them once and they investigated it. It's no cost to you. You might as well call AT&T and report it.
your dumb friend or someone found out your number and punched it into aim. deal with it.
DO NOT REPLY.
Replying *anything* only confirms to them that this is a real phone number. The "choice" to opt out is an illusion.