Who is in charge of keeping the rings?

I think traditionally it is the best man. I did it for my brother but I wasn't given the rings until a few hours before the ceremony. Many people have non traditional weddings or modify the traditions to their liking. Hey its your wedding, do what you want, a lost ring gag might be funny, or a little slight of hand to put extra magic in the moment. Slip the rings in the pocket of a guest in the front row and "accuse" them of stealing the rings! I know this probably will never happen but it would be funny.