Hello. I have been planning a trip to Spain. Last leg, is Granada. So for returning home, I figured we would head back up to Madrid either per our rented car or take the train ... and then we would leave the next day. Now after reading a post. I am considering taking a plane from Granada to Barcelona ??? Is this worth it ? Getting out of airport and into town, seeing what we could that day and then fly out ? Any imput would be appreciated. Thank you.

I just checked your previous posts. Are you still planning to do Madrid, Toledo, Sevilla, Ronda, Nerja, and Granada in 10 days?

And are you thinking of flying from Granada to Barcelona in the morning and then leaving from Barcelona to the U.S. that same night?

I'm afraid, I have over done this vacation, with too much running, but yes we have planned 3 days in Madrid, with a day trip to Toledo, then to Seville, for 3 nights. Going to stop and see Cordoba on way to Seville. 3 days Ronda, 2 days Nerja, Granada 2 days and then travel somewhere to get a flight the next day.

""" Is it worth it""""
In a word no.
train times
http://www.aena.es/csee/Satellite?ci...=Page&MO=1
bus times
http://www.aena.es/csee/Satellite?ci...=Page&MO=1
taxi information
http://www.aena.es/csee/Satellite?ci...=Page&MO=1
left luggage is near Terminal B
http://www.aena.es/csee/Satellite?ci...=Page&MO=1

rebeirasacra, for future reference, it would help if you would use tinyurl to shorten your links:

http://tinyurl.com/

Actually, Barcelona's airport is close to the city and well connected by train or bus.

If the other option was spending the day on a train or car ride to Madrid, I don't see much difference in spending that time in Barcelona.
You probably already guessed that you will not be able to really see Barcelona in one day.

IF you decide to do it, I would take the bus or train from the airport to downtown Barcelona, and start with exploring the Old Town and Cathedral. Walk thru Born district, visit Museu Picasso, and the market hall. Walk further towards the Old Harbor / Port Vell. Have lunch at one of the restaurants outside Palau del Mar overlooking the harbor, or at one of the Xiringuitos on the beach promenade.
Take subway to Sagrada Familia and visit. Plus another Gaudí building in Eixample, if you can handle any more sights.
Go back to airport.

I would probably feel a bit too rushed on my last day doing this, but given the proximity of the airport and city, there are many cities which would be worse for a 10 hour itinerary. You'll probably want to come back for more.