One idea to escape our cradle
Kilston, Steven,The Project: An Observatory/Transport Spaceship for Discovering and Populating Habitable Extrasolar Terrestrial Planets
Ball Aerospace & Technologies Corp., 1999.
March 8, 1999 JPL Talk, Online Viewgraph Presentation (661 KB PDF)
http://www.interstellar-probes.org/resources/TheProject.pdf
Though I still that Artilects will be the ones doing the real star exploring
by then, if we want to get off this planet in our current state, this is
one way to do it.