Didn't see a thread on this yet...
There is a swap meet tomorrow, Sunday 1/28, at the velodrome in Carson (Cal. State Domiguez Hills campus - near the Home Depot Center). $5 at the door, children under 12 free. Track races are scheduled as well.
I scored some killer deals at this swap meet last time I went - back when they had the old track in 1993? Not track specific.
Opens at 8AM and closes by early afternoon (not sure when).
EDIT: fixed date.