this is even the case for those tags, if being used in xml-files.
i think it's important to mention that because i searched hours for the cause of an issue when i used jQuery to load an xml-file which contains <object>-tags for a different purpose.

Instead of using the full selector to access a given element every time, you will use that selector only once, store it to the data element (for example, $('#myData').data('myElement', $('very-complicated-selector'))), and from then on, if you need to access the element, just do $('#myData').data('myElement').

It's like using the technique of caching a selector while you use it, except that this will permit caching throughout the life of the script, instead of selecting the element, caching, doing work, then coming back later and selecting the element again.

// store anonymous function in .data()
$('#el').data('myFunc', function(text){ alert(text); });
// alert the string “Hello!”
$('#el').data('myFunc')('Hello!');

Are there any drawbacks to doing this?

I'm no javascript expert, and I'm still not real clear on where jQuery is keeping this data, and how well it cleans up after itself. My concern is primarily if I'm creating and destroying a number of DOM elements on the fly, and attaching functions for use with these temporary elements, will there be any performance issues versus, say, referencing a more permanent function:

// define permanent function
window.namedFunc = function(text){ alert(text); };
// reference permanent function within .data()
$('#el').data('myFunc', namedFunc);
// alert the string “Hello!”
$('#el').data('myFunc')('Hello!');