Customizing Header with PHP (args from title)

I've seen various discussions regarding customizing the header/footer with php to being in data from the current view - similar to what you can do in title. I haven't seen any real definitive answers, however.

I would like some assistance in building some php that will customize the header based on the current view. In particular, I am doing a location directory view. So something in the header like:

Below you will find people in $1.

I've seen using arg(1) or something along those lines, but I would like the expanded names like those provided with $1 in the title field.

Any help would be appreciated.
Thanks!