In case there was any question, we live in a very Catholic part of the country. It's possible I just never noticed these things before, but I noticed they were selling something at the grocery store that I don't think I've seen before: a "fresh palm cross."
Terrible Catholic that I am, I had to do a little research to remember that the Sunday before Easter is Palm Sunday, so I guess these are to be used in connection with that. I think, though, that the fresh palm cross must be used in cultures that I haven't been around much. For example, wikipedia seems to imply that these crosses are more Eastern European, and not, say, Mexican, which would explain why I don't remember ever seeing them in L.A.
Note: in doing my research for this entry, I stumbled upon USC's motto, which is: "Palmam qui meruit ferat." This means in Latin, "Let him bear the palm who has deserved it." Apparently the palm branch is a symbol of triumph. Good to know!