A great thread on Facebook started by my friend Elisa Camahort Page.
She pointed to a Slate piece by Farhad Manjoo (another friend!) that says you should never put two spaces after a period that ends a sentence. I certainly agree, and while I was taught by my typing teacher in 7th grade, Mr Corwin, to type two spaces, I learned later in life this was a mistake.
Anyway, I pointed out that the web agrees. You can type as many spaces after periods as you like, the browser will only show one.
I demo'd this with a comment, and added four spaces after each period. The browser only showed one space, even though Facebook dutifully sent four.
I love it when technology gets something right.
I suggested giving Tim Berners-Lee a big hug next time you see him. Or it might have been Marc Andreessen who made this call.