You don't normally use an NPN switch to source current into an emitter load because in order to turn on the transistor you have to forward bias the base-emitter junction, so the voltage on the base has to be ~0.7V higher than what's on the emitter, otherwise the B-E junction isn't on.
In that thread, the little picture posted with 0.6V B-E shows that. It's just not showing you what the base voltage actually has to be to do that (+V + 0.6V).
Thank you Mike for providing the terminology - this circuit is called an emitter-follower and appears to be most commonly used as an amplifier for AC signals.
An in-depth explanation may be found in Introduction to Transistors, a presentation for Physics 275 at Ohio Wesleyan University. This presentation is pretty technical with all the nitty-gritty details.
This circuit may work well for some applications - just understand the details before soldering it together for maximum happiness.