I don't know about in the US, but in the UK the flexible trunking(This is the only link I could find, you can get it much cheaper than this) that they sell for outside wiring is the same stuff that they sell in computer shops as "Cable Tidy", but around a third of the price. If you cut it length wise, you can just fit it over the necessary cables. Mine's in a fairly unobtrusive blue, so it's not out of place in the house.