This was shot in Midtown Manhattan with a 28mm lens, which on a Canon 60D produces a normal field of view. I'm using this photo mainly for comparison (and also because I like it). The photos below are all shot with an 85mm f/1.8, which provides a 135mm field of view.
One of the most widely held shibboleths of street photography is that you can't shoot with telephoto lenses. Why? First, because the masters of street photography didn't use them. Second, because telephotos supposedly place you too far away from your subject for the required "intimate" feel of street photos. I'm here to tell you that it ain't necessarily so.
Let me make clear that I'm not referring to the long, large telephoto zooms you'd typically use for sports, scenic, or nature photography. These definitely tend to spook people and make it look as if you're on some sort of surveillance mission. Their extremely narrow angle of view makes it hard to get a quick grab shot. Their size and weight literally makes them a pain in the neck to carry around for more than a few minutes.
What I'm referring to are short telephotos, such as 85mm or 100mm on a full-frame camera or 50-70mm on APS-C. These are generally referred to as "portrait" lenses, but there's no law that says you can't use them for other things. They are particularly useful for cropping out visual clutter. They thereby simplify your compositions. If you're into the "street photography esthetic," however, you have to be careful not to crop out too much, otherwise you lose the sense of context that tells the viewer you're making a social as well as visual statement.
As far as technique goes, my suggestion would be to shoot at ISO 400, even in bright sunlight, and to keep your shutter speed no lower than 1/500 second. You want to be able to shoot fast, without worrying much about camera or subject motion, even if your lens has image stabilization. Also try to keep your aperture in the neighborhood of f/4.0 to f/5.6. That way you'll have enough depth-of-field to compensate for minor focusing errors but not so much that distracting backgrounds are in sharp focus.
Would I shoot all or even most of my street work with a telephoto lens? Definitely not. I'm more comfortable with shorter focal lengths and generally prefer the results. This mean I can't put one to good use if I'm in the mood. It also doesn't mean that you can't use one if you want to. Go for it. You just may find you love the results.