After discussing with Andrew Luetgers some improvements that could be done to the Object Cache plugin, I updated the plugin to a new version.

The new improvement is that now you can store a selection automatically:

// Will store in cache $("#sidebarNav") with #sidebarNav key

This will let you avoid doing $("#menu").cache("menu"), which is a bit redundant. Now by doing $$("#menu") you will be able to store it in the cache and retrieve it automatically. There is also a reload option that you can pass to that call in order to, well, reload the the cached object with that selection:

// Will reload #sidebarNav with $("#sidebarNav")
$$("#sidebarNav", true);

You can grab the new version of the Object Cache plugin here.