I have several camping gadgets that I can't live without!!
I have an air mattress and a rechargeable pump! Actually takes up less space than my foam mat I used to have and a lot more comfortable!!
On my December Ft. Wilderness trips, I actually set up two tents. One is my 10x10 dome that has great ventilation and is really comfy to sleep in. The other tent I set up is for my "stuff". I usually fly down for the December trip, so I refuse to be cramped up with my stuff in the tent for a week.
I also set up a sun shade/rain fly in front of my tent so that if it does rain, I don't have to squidge into rain gear inside my tent or bring wet rain gear into the tent.
I also have several bungy cords and also bring lots of biner clips (also know as "D" rings) for hanging stuff such as lanterns from the inside of the tent or the inside of the sun shade.
Another thing I find handy are cable ties. I usually pack my stuff for Ft. Wilderness and other longer camping trips into a large rubbermaid bin and use cable ties to make sure they stay shut securely. They are also good for attaching lights to awnings and hanging things on the inside of your tent.
I guess when I go to WDW this December, I will have to attach a knife with a cable tie to the outside of my bin that I will check as luggage so that I can get my bin open once I arrive, since I can't have the knife in my carryon.
When I'm camping with electricity such as at Ft. Wilderness, I always bring a small fan with me that helps fight the humidity and dries out the inside of the tent during the day.
Although, I guess my favorite gadget is my big folding chair with arms and cup holders. That thing goes with me everywhere, camping, ball games, picnics, you name it. I love it!!