Chris,

Ask and ye shall receive, no just kidding, there's one there already, see the little "search" link at the top right of the Forum window, to the left of the "Membership" box. That will allow you to search all posts on the forum.

When you go to the search page it even has fancy advanced options that will allow you to search by user of by sub-forum, you access the advanced search by clicking on the little down arrow.

I suffer from the same desease Crisc, whenever I look for a vacuum cleaner I find TV remote and when searching for the sink somehow I locate a beer in the fridge