If you wait a couple hours, you'll have only CO2 in the head space. Then you can "swirly" the hops around in there without oxidizing your brew. I use the plastic carboys so I can just tilt the carboy and do a swirling motion. The hops will swirl down into the beer (at least the pellets do... I assume it does the same with whole hops). It will all float back up, by while its doing that, you are increasing surface area contact. You can do it a few time while you dry hop. I usually cold crash for a couple of days which helps to settle out all the particles.
This is a method that the brewer from Lagunitas recommended to homebrewers during an interview on Jamil z's show about cloning the Lagunitas IPA. He actually said to swirl it 48 hours after adding the hops. I assume that's to be sure there's no oxygen in there because, from what I understand, swirling oxygen into your beer at this point could oxidize your beer and make it taste like cardboard... not cool.
I actually just dry hopped that clone tonight. I'll see if I can film a "swirly". I'll post a youtube link...