show forum in multiple categories?

[Langers]

I want to be able to direct users straight to category pages but also show forums from other categories (i.e. 'General Chat') on the same page.

Something like this: http://www.tyresmoke.net/ubbthreads/...,22,25,26,27,8

Where the 'VW' category is shown, along with other 'general' forums/categories.