For most purpose i.e. skis and bikes a hitch attached rack that swung out of the way would work. For Kayaks you are left with either using a different vehicle or a much cooler albeit expensive option:
SylvanSport | the GO | Lightweight Unique Camping Travel Trailer
I totally love this 'cooler albeit expensive' option . Putting rails on the top so that it can accept almost any Thule or Yakima rack (allowing your own custom configuration) is brilliant. I'm having a hitch put on my Prius & ordering ... thank you for this link.