Update: Sanders yielded the floor at about 7 p.m. The clerk called the roll.
If you are near a television, turn on CSpan2. If you are online, watch the feed here. He has held the Senate floor, more or less, since 10:25 a.m.
Also you should check out isberniesandersstilltalking.com.
Alex does some of the early blow-by-blow here.
Also, Politifact is doing some live factchecking.