The #1 most asked question of all time has now been answered for all eternity. Since the new release, adding weapons to your place is easy and fun.
If you can see how to insert a weapon into your map, you can probably also figure out how to insert a nice custom skybox (hint: see that Skybox tab in the Toolbox?).
One of the nice things about adding weapons to your map in this way is that if we later improve those weapons, you will get the new weapon without needing to update your level. For this reason, it is suggested that even people used to copying scripts around use the weapons from the Toolbox unless you are doing something special.