In future, I will only send this link to @switchingsoftware when people ask me again what is good for what on the PC. Unfortunately, many still say they are skeptical, but in reality they are too lazy to learn and teach themselves.
Don't want to waste any precious hardwood to make a quick & dirty drill guide?
Just use one of those nasty big knots that aren't good for much else. Because they're plenty hard! :)
Straight through the knot with the drill press (which is in the garage) and now I can use this knot to make straight holes anywhere with my hand drill. The bottom is flat.