Drying one's clothes on a laundry line has to be one of the most inefficient ways to save electricity I've ever heard of. Seriously, get your insulated well and lay off the air conditioning a bit; you'll be doing a lot more good for a lot less effort.
Really? It only takes a couple minutes longer to hang the laundry rather than dump it in the dryer; it takes longer, but then, I'm not going anywhere. As a renter, I can't insulate the building any better and I already don't use A/C at all, so I'm afraid I can't take your other suggestions. :)