Not to make this about Lance, because that debate could go on forever and will never be proven either way, but he can't possibly have been clean. I simply don't believe he's so much better that he can not only beat the entire world, but do it while they're juiced to the gills and he's clean.
I once read a really fascinating article by an amatuer cyclist who started taking a lot of performance enhancing drugs, legally, at his own expense, just because he wanted to see how much they really did. He said it was amazing; he never got tired, felt like he was invincible and could ride forever. His riding buddies noticed immediately, and he had to stop himself from winning races (because he wasn't out to get anything he didn't deserve). In short, drugs provide a very significant advantage, and I just can't believe that anyone clean could have dominated a world full of dirty athletes like Lance did.
Anyway, with respect to Landis, why do these guys bother lying? He had to know the test was going to show it wasn't natural testosterone. Just once I'd like to see one of these guys stand up and say, "Yes, I did it. I took drugs because it was the only way to compete at this level, and you caught me. I'm sorry I had to take them, but I'm not really sorry that I did it because I couldn't be a professional in this sport without them. Now I'll just accept my punishment because I cheated, and everyone knows it, so I'm not going to insult the sport and the fans further by denying it." I mean, do they think they're fooling anyone with these denials after the tests come back positive?