I got this mail within a few hours after I sent the picture to Ms Karen Nisbett; 

  Hi!  I think your unidentified flower is Mandevilla suaveolens, or
Chilean Jasmine.  I'm including a URL for a website which sells it, and
has a photo and cultural info, plus description.  I've seen this vine
before, but because of the cold winters here it can only be grown as an
annual (I think some people do bring it inside and winter it over that
way.  In areas where the temps stay warm all year around, these things get
huge!  They are very beautiful.
http://www.floridaplants.net/html/madevilla.html

Regards,
Karen Nisbett

I took these pictures in front of my office, the vine is covering whole section of the house opposite.  They seems blooming all the time.

It makes a big tree.  The trunk is around 3" across.

Thanks Karen,

April 2000