Create filter multiple selection

[eluser]danmontgomery[/eluser]
Like n0xie said, I would use jQuery with ajax for this... You can find bunches of examples:

http://www.google.com/search?q=jquery+mu...select+box

Something like: http://www.senamion.com/blog/jmultiselect2side.html

Not saying that's the best (or even a good one, I haven't used it), but you should be able to find something that will closely meet your needs.