I doubt it:

I am sorry. I will try to find a way to get you a ringtone :)

Doesn't really sound like our man, does it?

Tom Waits 'twitters'. It would be so wrong somehow.

...thereby fulfilling a Tom Waits lyric.
The following is representative of his attitude to mobile phones and technology, from the gig I saw in Dublin:
"Your phone is also a camera. Well, my sunglasses are also a tricycle".
The idea of him flogging ringtones - while tweeting - is laughable.
What's more, I don't doubt that this impersonator will be hearing from his legal team shortly. Waits has been known to have a sense of humour failure when it comes to using his identity / likeness for profit. As many an advertiser has learned to their (substantial) cost.

is played at the beginning of every episode of The Wire, bringing in, I should imagine, a good deal of cash. It can't be him Twittering.

been suspended due to `'strange activity"!!