I got some at Walmart last night, $3.47 or some dang odd ball price for a string of 75 I want to say. They are "split" into two sections so you can put a blinker light in one and only the front half or back half will blink. It comes with two blinkers so you could have the whole thing blink, but they won't be synchronous.
They also have "garland" strings of 75 that are 9' long. The lights are clustered in groups of three down the strand.