I know google earth is talked about quite frequently, as are discoveries of aircraft in flight caught in google earth. well, search no more! heres a link that if you open it and click on "open in google earth" gives you all found airbourne aircraft worldwide in your "my places folder" it pretty neat! especially the ones with contrails!
also, keep in mind that due to constant pasting of images, they are not nessesarily accurate i.e. 3 planes 5 feet apart in flight. i am posting this because i know there are posts about individual findings, well, here they all are!
Also, dont get this confused with the live 3-D flight tracking http://www.fboweb.com/fb40/login/ft.aspx
these are images in google earth that are in some cases years old.