My best friend (who I've known for around four years now~) and I tend to have similar taste in necklaces, so we usually (unintentionally) buy the same necklace or accessory, but in different colors. xD
I have a few 'best friend' necklaces from Elementary and Junior High School, but I still wear them from time to time. c: I think it's a good momento for wonderful memories shared with the friend. C: