When pressing F10 (or Ctrl-F10) to show a program’s open windows, you can press Cmd-Tab to cycle through all running apps, showing the icons across the screen as the normal Cmd-Tab does. You can also scroll through running apps in Exposé by pressing Cmd-` (back tick), but without the icons. Apparently this will also switch you from all windows Exposé to only one app at a time (the F10 effect).