I just found out today that some of the contestants on Expedition Impossible are blogging about their experiences on the show. Here are links to the ones I know of. Feel free to add more if you find any from other contestants.

Eric (No Limits)
Episode 1
Expedition Impossible Behind The Scenes #1 | The Blind Viewpoint

Episodes 2 & 3
Expedition Impossible Behind the Scenes #2 and 3 | The Blind Viewpoint

Jeff (No Limits)
The World of MountainVision

The Gypsies
Expedition Impossible | The Modern Gypsies