From everything I've been reading and hearing from some die hard trail camera guys, the new Moultrie I-40 and I-60 are the way to go. Both cameras are taking excellent photos and are IR so they don't have a visible flash. From what I've heard battery life is pretty good too. The I-40 is 4.0 MP and the I-60 is 6.0 MP. The only other difference is that that 60 has a built-in image viewer and the 40 does. For the $60 difference I don't think it's worth it. Personally, I think I'm going to pick up an I-40 next.
Check out the full review on the I-40 here:
http://trailcam.com/blogs/trail_camera_reviews/archive/2008/03/06/moultrie-game-spy-i-40-infrared-trail-camera.aspx