Tip: Global shortcut to popup OmniFocus window
 

Until it's built in in OmniFocus (hint) this is one way to get to your next actions fast. Assumptions are you are using quicksilver, and you are using hide, not minimize,

Quicksilver: add a trigger, in subject enter '.' to switch to free text, then this

[FONT="Courier New"]
tell application "Finder"
activate application "OmniFocus"

end tell
[/FONT]

In the subject, select Run as applescript. Assign to your fav keyboard shortcut.

Actually, just setting a trigger to [B]OmniFocus[/B] | [B]Open[/B] gets that result a bit more simply, and will also restore a minimized window.

or using LaunchBar
command-space (or your choice of LB activator)
"of"
enter