I'm also constantly tempted to buy a 1975-style Red Sox cap...that year, the dome part was red, with a dark blue bill. I'm a sucker for red, and think that looks much nicer than the current all blue version--that's just the same as a (ptooey!) Yankee cap with a "B" replacing the "NY."

I do own one of the all blue ones, and wear it with the traditional facial expression of a Red Sox fan.