You want to use a thermometer with a probe which can stay in the milk during steaming, instead of an instant read -- which not only ain't so instant, but forces you to stop and restart steaming if you miss your target. You want something you can keep an eye on while the wand's in the pitcher.
With the probe in the milk from jump street, the thermometer doesn't have to overcome inertia to get a reading. By way of example,
this is the thermometer Chris uses.
idrinkcoffee's stick-on liquid crystal thermometer seems like a good idea if you don't mind the way they look on your pitchers. Slawek's a champ, but those thermometers would make me nuts. If I were the one in our couple who drank the milk drinks I'd probably put up with it, but since I'm not I use the finger on the side of the pitcher method like the other trogs.
BDL