[jQuery] Filter select options values as you type

[jQuery] Filter select options values as you type

I´m looking for a plugin that filters the mached values of a select element.
It´s something like Live Search plugin that´s John´s posted in his blog, but instead of filtering a list, it filters the options from a select element.
There´s anything like this?
If there´s not, what should I aim for and what should I do to develop something like this?
Thank you very much :)