We've heard of grocery stores accepting rivals' coupons, but this is a first for us: Waterloo Records takes chain competitors' gift certificates and cards! From their email sent out earlier today: Have you received a gift certificate or card* from a national chain store that carries music or video (Walmart, Best Buy, Target, Circuit City, Borders, Barnes & Noble, FYE, etc.)? Do you prefer to shop locally, or maybe you'd like something out of......