I have a "donor" circuit board (from an old copier) that has several of these M5248 IC's on it M5248P Datasheet(PDF) - Mitsubishi Electric Semiconductor. It seems like they should be useful for something. On the copier I'm guessing they were operating solenoids or motors.
A darlington is simply a pair of transistors hooked together to give a much higher gain than you would normally get from a single bipolar transistor, so thay are capable of driving higher currents with a smalled input base current.
Downside is double the voltage drop.
You'll have to forgive my ignorance--I'm still learning. But does that mean I could switch a 12 or 24v solenoid on/off with a 5v signal using this chip?
Front page of the datasheet:
"Features
High output sustaining voltage to 80V(M5248P)/60V (5286P)
High output current to 1.5A
Integral diodes for transient suppression.
does that mean I could switch a 12 or 24v solenoid on/off with a 5v
Judging from the datasheet, I'd say that's what they were designed for.
Okay, thanks. fyi I'm not brain-dead...just an electronics novice that wants to be sure of what I'm doing 
That's totally awesome. I have access to so many old copiers and they're just loaded with all kinds of motors, sensors, switches, clutches, ICs, displays, wires & plugs, etc. Some of it is heavy-duty stuff that I'm sure would cost a pretty penny if I had to buy it...
For a lot of electronics background questions, I have found Wikipedia tends to have a good source of base knowledge:
It may not answer your question in plain language, but it will give you detailed information about the concept.
Awol
I presume what you meant was that you would need twice the base drive voltage over what a "normal" transistor would need (ie somewhere around 1.4 volts) The collector-emitter voltage drop (circa 0.7 volts) would remain the same as normal.
James, I appreciate the help. I do actually do searches and such before I post, but here I was looking for the "plain language" answer as you so accurately put it. I have enough knowledge now that I should be able to start experimenting with this IC and once I start doing that, THAT is when I'll really learn (I'm a very hands on learner).