Getting the select menu's droplist to have multiple columns instead of one? Having difficulties

Getting the select menu's droplist to have multiple columns instead of one? Having difficulties

I'm currently working with the select menu:  http://jquery-ui.googlecode.com/svn/branches/labs/selectmenu/index.html

Problem: My droplist is getting quite long, I want to shift it to another 'column' instead of having a very long scroll bar.

Below is an image that I've made to visualize what I want, div is my droplist, elements are my droplist items:



I hope someone can tackle this problem... I've no clue how to implement it.