@ElizaBennett - I mostly used whatever was handy, too, but I did have a couple of those cute monogrammed burp cloths for my first baby. One my aunt made because she just likes to do embroidery projects, and another my sister bought at a craft show. They were basically cloth diapers with embroidery on them.
They may be overly fancy for something baby is going to spit up on, but they do at least, in my experience, work just as well as dishtowels or blankets! They're one of those things that I think exist for people to buy as presents for first grandchildren, etc. No one who has recently had a baby would buy one, but they are cute for the shower!