I somehow failed to notice this thread until now; sorry about that.
I'd be happy either way on this.
In L4W and LEB, we've doubled XP awards, and it works reasonably effectively. It does require more frequent XP awards; you don't want to bunch up awards from a handful of encounters, time xp, and quest awards all at once, or PCs will pass more than one level at once. We usually manage to avoid that by handing out XP more often, possibly multiple times a day, when there's a reasonable break in the action. That works well for 4e, where things like xp and training are a bit more hand-wavy; might not work so well in 3.5e. We'd have to try it and see.
On the other hand, I do agree with the other judges that levelling does go reasonably quickly, when you've got an adventure that moves along pretty well. Although, I would say that getting from level 1 to 2 takes an unreasonably long time in a lot of cases. It seems to get better from there, for some reason.