Well, I have to say I hate washing lines, always have!
I use a big airer and carry that in and out... its currently out on the deck. It dries well even on a cool sunny day (like today) but saying that I have a tumble dryer now, and I never had one before, this is partly becuase we have another person in the house (he may be small, but produces a lot of laundry) and the stuff doesnt dry very fast in winter, and when you get a wet Auckland week, you are totally stuffed for getting anything dry.
Sun is also good for getting stains out of pale clothes...
So basically if the sun is out, you clothes should get dryer, faster...