Not sure what you mean. Beyond the various in-point/ out-point shortcuts and the Ctrl+Up/Down arrow (or Ctrl+Shift+arrows) I'm only aware of some "select below" script that would select all layers below the current one that would provide such a quick selection....
Thanks for the reply, Mylenium.
...I must be confused by another prgram with this functionality. Damn!
What script were you refering to?
I'll give AE Enhancers a shot.