You have encountered the most obvious difference between drop down lists and pop up menus. There are several possible work arounds.
Simplest is to add the name field from People to your Main table layout. When you select the person in the drop down, the drop down still displays the ID number but the name field from People now displays the selected name. you can place both fields side by side or, if you use the behavior settings in the inspector to deny access to the name field, you can even place the name field on top of the drop down list. When you click on the name field, the drop down list behind it deploys.
It's also possible, with scripting, to use an auto-complete value list of names to select and enter the associated ID number: http://www.4shared.com/file/plr_jbkk/EnhancedValueSelection.html
Thanks a lot, at least now I know I'm not crazy. I'll try both these options out to see which is the best fit.