In message , at 14:49:35 on Fri, 10 Feb
2012, tim.... remarked:
I have blinds on my windows to stop the sun from waking me up in the morning

what other purpose do they serve?

Depends what overlooks your windows. I've seen houses where the only
thing stopping passers-by getting a good look at someone sat on the
toilet is a blind.
--
Roland Perry