As far as I can see the only sensible option is a global object. If you want to access something from anywhere it needs to be global.
If you look at most utility libraries e.g http://underscorejs.org/ you will see the same thing. They use a global namespace (similar to your MyApp object) which is just named '_'.
If you try to add the functions to each object individually you will be duplicating them in memory for each object which is a waste.