In Eclipse (I'm using 3.4.1) you can create "favourite" run configurations. These simply appear fixed at the top of the list of Run configurations.
Is there a way to create a shortcut to a runtime launcher in the Eclipse toolbar itself?
As far as I know, the only way to do this is to code it your self, which is why I never have. I think you have to subclass ControlContribution (org.eclipse.jface) and implement createControl(Composite). It's possible the RCP Book provides a cookbook solution to this problem as it's often asked.
It's possible you could hack an existing plugin menu, but I'm not really sure you want to go there either.