Carl Fredrickson is a chubby little boy with big dreams to be an explorer, but nothing else really going for him.  While on a mission in a deserted house he meets a fellow explorer, Ellie, who is everything he's not. Over the years they somehow end up together and we see a glimpse at their life over the next 60 years. 
  They share a lot of happy memories, enjoy fixing their new home and decide to save for a "big" adventure to South America, but meet many obstacles on the way - including medical bills for the accident-prove Carl and a very sad section when they lose their unborn baby.  They never reach their goal and Ellie dies leaving Carl alone.  To make things worse, a developer has bought all the houses around them and wants their land.  Under mounting pressure, he hits out at a well-meaning construction worker and is about to be sent to a retirement home for his own good, leaving the house with all the memories behind to be demolished.
  Next day when the men in white coats arrive, he asks for a few minutes to say his goodbyes ... but suddenly thousands of helium-filled balloons erupt out of everywhere and rip the house from its foundations, and then up into the air. Using a set of wings through the side windows(!), he sets sail for South America ... but after a tapping on the front door realises that he has a passenger wearing bright-yellow with a huge back-pack that wasn't in ANY of the earlier shots as the house was flying.  Anyway, this is 8 year-old Russell, a boy-scout with a terrible father whose goal in life is to gain his last badge -  one for "Assisting the Elderly".
  Unable to just dump him out the window, together they set sail for Panama...

Using Russell's GPS system, they make it to Panama in no time with the help of a little tornado.  Wanting to put the house down in the exact spot that Ellie drew in a picture, they decide to walk around a canyon dragging the entire building with them rather than just hopping back on the house to fly the short distance over. On the way they meet a rare Ostrich-type female bird they name Kevin (who gives one of the funniest moments of the film that you'll have seen in the trailer), and stumble upon a dog that can talk through a mechanical voicebox-decoder.
  As it turns out, the dog belongs to disgraced explorer Charles Muntz (Carl's boyhood hero) - who happens to be a nobel-prize winning type genius when it comes to dogs ... and also a serial killer when it comes to fellow humans.  I know, exactly, but in a friendly secretive 'Incredibles' style way so kids aren't too scared.
  He realises they found the bird in 5 minutes - the same one that has defeated him for 60 years, isn't too happy and decides to kill them too and take back the bird and her young ones to the US to clear his name. Carl and Russell defend the bird with their life as the balloons on the house keep popping.
  Soon the house is almost destroyed but Carl comes to his senses and is finally the hero again -- he dumps the house, defeats Muntz on his giant airship (we see the bad guy fall from a great distance clutching just a handful of balloons ... he's definitelty dead) and then travel back home. Meanwhile the house floats down to land in the spot they wanted all along - a prime spot of real estate.
  Back home, Carl fills the role of the father-figure (or more grandfather-figure) to give Russell his final medal-badge in a teary-moment on stage at the scout ceremony in front of an audience, they turn to face the crowd ... And then the movie ends with the Rebel Alliance applauding and Chewie facing the camera to growl before the credits roll. No, wait, I'm thinking of something else...