What I really wanted for Christmas was a drill press. Being able to drill a hole that's dead-nuts perpendicular to your material is a crucial DIY skill, and one that I can manage most of the time by eyeballing my power drill—but I tend to screw it up when it really counts (i.e. on the last, or most crucial, hole of a project).
In an effort to solve this I wasted my money on the Rockler bushing-based drill guide above, which has way too much slop to be accurate, and the other two get crappy reviews, so I won't be ordering either. But until I can afford the money and space for a drill press, I'll just have to make do.
One of the problems with eyeballing a hand drill is that you can only see the bit from one angle. I just came across this Instructable designed to solve that problem:
Pretty freaking brilliant, I say! Much easier to eyeball if four drill bits are parallel than to guess if just one is crooked. You can probably figure out how to make this on your own, but the full Instructable is here.