My friend Mike is in a band, and my friend Jocelyn is in a band. Last week, Mike emailed me to say he had met Jocelyn at a concert, and ask if I wanted to go to see a show they've got coming up. He was unaware that I already knew her...funny, but not that big of a coincidence, given that he saw I "like" the band on Facebook.
Later, however, Mike was telling a friend about this coincidence while they were having dinner, and at the very moment he was talking about it, I rode by the restaurant on my bike.
(This is part of a subgenre of coincidences where the telling of the story yields another coincidence.)