I have to admit, I laughed the first time I saw a cordless screwdriver advertised. For a long time, I held the belief that using a drill as a screwdriver was for sissies. I also thought that battery-powered hand tools were a needless luxury, and kind of weak to boot. I now file those beliefs with the follies of youth, like my juvenile dislike of strawberries and Brahms. A perfect wild strawberry and the violin sonata No. 1 in G, Op. 78 changed my mind about berries and Brahms; here is what changed my mind about cordless screwdrivers:
The Makita LXT 18V cordless impact driver.
Screws are, for many (but not all) applications, better than nails. They hold tight, they don't make the two pieces you're joining dance a waltz, they make pieces of wood suck up against each other, and they are reversible. If you have this tool, you can bury a 3" screw in about a second, and you don't need the room or strength to swing a hammer. You can also undo the work of your predecessors, if (as in our kitchen floor) they anchored Hardy-backer to plywood with glue and zillion kajillion screws. You can injure yourself, but I've only Phillipsed my thumb once, and I've hammered the same appendage a lot of times.
Oh, and things that I thought were silly? The belt hook? I use it constantly. The little LED light above the trigger? Phenomenally useful in the poorly lit nooks one finds oneself in all the time, and I've used it as a flashlight at night.
I went out and bought this tool because I was starting to feel guilty about constantly stealing it from our general contractor. The Real Doctor's brother may be getting one, for much the same reason. It just rocks.