Heard about it earlier from Facebook! He made original 60s NBC Trek worth watching (I saw it through from the three remastered DVD releases of the same).
I saw Nimoy speak a few years ago at a convention (2010?). He was eloquent and funny, as always. I wanted to do the personal meet and greet, but we were pressed for time (babysitters!) and had to go. I'll always be sad I didn't take that extra half hour to shake his hand. Still, I'm glad I did take a few hours to go and hear him speak. That was only the second time I saw him; the first was in 1975 when, as an 8-year-old, I won tickets to a New York Star Trek convention and saw the entire cast of the original show.
Sad news. RIP Mr. Nimoy. I remember my one "sighting" of him. I was in the drive-through line at Westwood's In-N-Out with a buddy when I looked in the rearview mirror and saw what I was 99% sure was Leonard Nimoy in the car behind me (I think it was an SUV). I asked my friend if that was him, he turned around and said "yup, I think his kid goes to UCLA" which is located in Westwood.