Just got Aperture Science today after about 4 days of trying the challenges on and off. The link to the Portal Walthroughs site was extremely helpful. I watched every video available and had to redo specific areas repeatedly until I got it just right and made it to a spot to save. All the videos are useful so watch every one of them that is available; you may mix and match different techniques in each video to get your gold on the map.
I thought this game might not be possible to get 100% in on the console because the guys in the videos seemed to be using the PC version of the game, and the mouse is so much more accurate than the 360 controller, but I proved myself wrong. It just takes patience!