velo2000

I did last summer in Anchorage. I stopped at REI and the bike shop folks gave me a cardboard box for free. I flattened it, then folded it accordion style into a plank like shape. I strapped that lengthwise across my rear panniers. It stuck out both sides a couple feet, so I had to be careful not to hit anything (or anyone), but I made it to the airport ok. At the airport, I unfolded it and it returned to its normal shape and held up just fine. Here's a pic on the way to the airport:http://www.colovelo.com/wp-gallery2.php?g2_itemId=3561 and after packing my bike: http://www.colovelo.com/wp-gallery2.php?g2_itemId=3564

If you have a backpack, it might even be easier to carry a box folded like this on your back. I've carried a snowboard on my back while on my bike and it wasn't a problem. Less danger of hitting something than with the method I used in Anchorage.