I used to when I had friends on the scene working in the same city as me and as it happened, we were all quite similar in basic stats. Although I'd never recommend them to some random on the phone because if he turns out to be a knob, I'd feel implicated. But if its someone I've seen before and I just wasn't free at the time/s he wanted then I would.
I wouldn't recommend a dude I don't know to a woman I don't know, and yea... if its not a regular or someone I haven't even met before, I think it quite rude.