Chosen just may be the definitive jQuery plugin for cleaning up drop downs in your MVC applications.
Add this to your document ready event handler:
and enjoy the magic. Everything else works seamlessly. You don't have to worry about binding. It still works as expected.
If you have wired up an onchange event handler, you have a little bit of work to do but not much and the look is quite impressive.
As an added bonus for long drop down lists, the default behavior gives you a searchable box at the top of the list.