Not Led Zeppelin, but actualy lighter-than-air craft criss-crossing the skies. Although certainly they would not be as fast as the current aircraft the far lower fuel consumption and greater comfort of being in a vehicle that floats gently rather than ramming through the air to gain lift sounds wonderful.
Add on to that the realization that you will no longer need runways.
And that the craft will be comparably quiet.
And with the gradual reduction in the availability of fossil fuels this would become almost a requirement to maintain our current travel needs.
This is right up there with my want for electric trains across the globe, no really, just like the trains we had as kids, only adult size. In reality since current locomotives are diesel electric for a simple conversion you would only be removing one step out of the process.
Anyway, here is the link, check it out!