You can get power drills pretty cheap (under $40) every once in a while especially if they are on sale. They aren't high quality, but they're fine for the odd job around the workshop or house.
The drill I have my girlfriend bought me for $37, and it came with a hard case, a whole assortment of bits, and a ratchet screwdriver, only one battery though. It would be no good for a contractor or even a regular handyman, but for me it get's the job done.
But if you really don't want to buy one, a hand held screwdriver will do the job, it'll just take more time and effort.