Wine charms are cute and all, but they only work on glasses with stems. To keep track of your wine (or whiskey, or beer) no matter what glass it's in, consider using washi tape. Photo by myam.
Washi tape, which is basically really pretty masking tape, sticks well to glass and comes in all kinds of pretty colours and patterns. Just write your name on it (or your guests' names) and stick it on your beverage, preventing drink theft and the spreading of cooties.