Folks, when you tile your own bathroom, please don't use grout to fill the seam between the tiles and the bathtub or the joint between two adjoining walls. Instead, you should use caulk, like you're supposed to. That way, when the walls move slightly -- as they're prone to do -- the joints won't crack and get mildewy, forcing the young couple that moved into the house to have to spend hours scraping out the grout and putting down a fresh bead of caulk.