The US has mail forwarding for 1 year, but that doesn't solve the problem, as you still need to update the source information with all the companies. I usually end up spending several hours changing addresses when I move. It's better to do this right away than to rely on the forwarding completely. Some places get the change of address info automatically and update their records, but it's never the ones you actually want (usually catalogs and marketing mail).
A PO box would be fine, but it's not an acceptable address with many businesses, so it's not a universal solution to the problem.