I’ve been following this tutorial(http://wiki.blender.org/index.php/BSoD/Introduction_to_the_Game_Engine/Creating_more_complex_game_levels_and_interactions#Collecting_pickups_within_the_level)
that shows how to create objects that disappear on contact, but I’ve followed everything it said and the objects won’t dissapear. Since I’m just testing it, my character is a sphere and the object is also a sphere, but when my character touches the dissapearing object, it doesn’t disappear. Instead my character goes right through it! I set up the sensors, controller and actators exactlly like whats shown in the example, picture, but it won’t work. Is there something wrong with that tutorial, or is there something I’m missing? Ive included some screens of the settings I have enabled under the Logic tab for the disappearing object and a screen of my character (the yellow sphere) going through the disappearing object (the white sphere). Any help would be great! 
The near sensor is bugged. Try switching that to a collision sensor and it should work fine. (Of course, you would have to hit the object to end it instead of just getting near it).
And the reason you go through the other sphere is because it is a ghost.
Thanks a lot for the help! Everything works perfectly fine now.