Josh Bowman runs a Twitter account @TopologyFact with neat notes about topology. I think he was inspired by John Cook’s various @XFact accounts. (Here X is a variable. MATHEMATICS!) I want to remember this particular link, and I figure some of you might like it, too.
RT @Thalesdisciple Beautiful series of lectures by Jack Milnor on differential topology, from 1965 MAA meeting: http://t.co/1YGH2PCUu7
— Topology Fact (@TopologyFact) July 13, 2013
Edit: Patrick Honner was kind enough to point out that @JohnDCook runs @TopologyFact and Josh Bowman runs @GeometryFact. He also has offered to start @TwitterFactAccountFact.
Circles and Tangents 
These lectures were great! No idea how they were received by the MAA membership at the time, but they’re rewarding to watch now.
I am glad to hear that. I haven’t actually watched them, yet.