Excuse my ignorance, but could somebody please tell me, if you fly into Dallas FW with AA at 06:05am and your onward flight (again with AA) isn't until 07:20pm, can you leave the airport and have a look around? Thanks!

Yes, and then you go back through security just as you would normally when you first arrive at an airport.

When you say "leave and have a look around" I assume you mean leave the airport property and see some of the sights in and around the dallas/Fort Worth area. With a 13 hour layover you have lots of possibilities. Decide whether you want to go to Dallas or Fort Worth (you really won't have time to do both). You will, however, need a rental car or taxi for transportation. DFW airport is mid-way between the two cities (about 15 to 18 miles from each) so allow time to get back to the airport and clear security.

Thanks very much guys. Yes, I meant have a look around Dallas! Would we (do you think) be able to leave our luggage at the airport (either checked in for the next flight - doubtful or in a left luggage place?) - that way we could take a taxi into town.
Great! Never been to Texas!
(This would be en route back from Honolulu to London)

Your best bet may actually be a rental car for the day, especially if you have carry-on bags. A car would give you mobility you wouldn't have otherwise.

To get from DFW airport to downtown Dallas I've used both taxi and shared ride shuttle van. Taxi was about $45 each way, and the cost of the shared ride van is about $20 per person each way, so two of you round trip would be more than a rental car. Prices may have changed.

What I don't like about the shared ride vans is that they won't leave the airport until they are full. Last spring I had to wait about 20min at the curb for a van to arrive - there was an agent there with radio so they told me which van was going my way. After about 45min we arrived. Not at our destination, but back at the starting point, having circled through each and every terminal finally to loop back and pick up more pax. I can think of a lot better things to do than circle the airport in a van.

There are no luggage storage areas at DFW (since 9/11 they have become extinct as dinosaurs). Since both your arriving and departing flight is on AA you should be able to check your luggage all the way through to your final destination. You will, of course, have to keep your carry-on bags with you.

A rental car will give you added flexibility when moving around the Dallas arera. If your budget allows you might consider hiring a car/driver for the "day". It will cost more than a rental car but you won't have to worry about transportation or how to get around the metroplex and the driver will take you anywhere you want to go..

Thanks everybody - I will bear all this in mind and think what's best to do. I checked the price of a rental car for these few hours, and it's not good ... $85!

You might want to look into taking the train (Trinity Railway Express) from the airport to downtown Dallas.

http://www.dart.org/riding/tre.asp.

I haven't done this since I live in the area, but if I were in your shoes, I would definitely consider it. It would take you to Union Station, which is connected to the Hyatt Regency Hotel. From there you can easily walk to the Sixth Floor Museum (about the Kennedy Assasination) and the West End tourist area. The Dallas World Aquarium is down there and the Dallas Museum of Art is also in the area. There's also a trolley that you can take to some neat areas as well.

Using kayak.com I found rental cars for as low as $50/day. Priceline is also an option.

$85 for a rental car is going to be cheaper than taxis. DFW is kind of isolated. I'd suggest having a plan. It's not as if you can just head "downtown" and find a lot of stuff within easy walking distance. There's a nice art museum in Fort Worth, and that city is more do-able, in my opinion. There are several museums and attractions in the same immediate area that are walkable.

There's some attractions in Arlington (Six Flags, etc., though those don't sound as if they would be your cup of tea).

Dallas is farther and has never appealed to me as much, but jayne1973 has made some suggestions that sound interesting to me.

If you like wine, you could visit Grapevine, TX which is VERY close to the DFW airport, and do some winetasting. I think they have about 9 wineries/tasting rooms, some nice shops and restaurants there too.

http://www.grapevinetexasusa.com/

Thanks all for your further suggestions. I think we might take a taxi to Fort Worth and explore the Stockyards. But nothing is decided yet (although the airline tickets are bought, so the 12 hour layover is certain!) Probably it would be cheaper to hire a car, but not sure we would feel like driving to and around a strange city between long flights.

Fort Worth would make a great day trip in this situation. If you are at all into museums, The Kimball and he new modern art museum are absolute must see places. I'd also advise renting a car - it will likely turn out to be cheaper than cab fare. DFW is in the middle of nowhere.

With the amount of time you mentioned, I think you should look into taking the TRE (link supplied by jayne). You can visit either Fort Worth or Dallas (or even both) using the TRE, and if you buy a day pass, you can take as much TRE and DART as you want to get around. I would NOT recommend the TRE if you only had 5-6 hours, but with 13 hours, it's certainly doable by public transport.

If you go to Dallas via TRE, you can connect to the DART (sort of light rail system) and get to many sites that way.

You *should* be able to have your luggage checked through to your final destination.

BTW, if you are in DFW on a Sunday, then the TRE won't work as it doesn't run on Sundays.

Thanks Seamus and yk - I will look into all this. It will be a Monday, so the Tre is a good option. Thank you, Jayne, for the link, by the way.

Just a word of caution: WEATHER DELAYS. Ok, two words, but delays, weather or otherwise, are so common I don't think you can assume you'll have that much time. I would try to rely on transportation that you don't have to pay for in advance, just in case your time gets really short.
If that does happen, maybe a day pass at your airline lounge would be helpful.

I think the SMU campus in Dallas is beautiful... close to beautiful homes, places to eat, magnificient buildings and a place to stretch your legs. I might head there if the weather was decent.

I'm no expert on Texas, but I agree with the suggestions of: 1) making sure your luggage is checked all the way thru so you don't have to deal with it and 2) NOT renting a car.