Question for Electrical/Computer Engineers...

I was playing around with my camera last night and I was taking photos of random objects and one of the things I grabbed was a 2GB SODIMM module.  I've never really looked at one closely before but I noticed that on the center of the board, on both the front and the back, were these serpentine traces.  What purpose do these serve? Any thoughts or ideas?

Update  via Twitter from Dave Jones (eevblog.com)

"It matches the trace length to the one next to it. For timing. RT @brianstuckey: what is the point of curvy tracks? bit.ly/u8zUX5"