[OS X TeX] Putting a banner in beamer

[Jason Davies]

dear list,

  I am ready just rejoined after we were all asked to do so, so 
thanks for having me back. I continue to be an almost complete 
newbie,  and, as ever, plead your indulgence.

  I have just started trying to use beamer,  but in my 
university, we are expected (for the kind of talks I will be 
giving) to have the college banner across the top, at least of 
the title page.
   you can see the effect at <www.ucl.ac.uk>.  they give us lots 
of PowerPoint templates, but of course no TeX ones.  I have 
tried to create the effect in beamer  without success (I first 
tried to use the logo, but cannot position it correctly and then 
I tried to work with the headline, to no avail).

   If there is a simple way to do this, or even a complicated 
one, I would be grateful to any tips. So far I can position the 
logo almost anywhere except where I wanted by messing around 
with the .sty file and so on. I would be surprised if no one 
else had faced this problem and apologise if the solution is 
well-known and simple, and I have overlooked it accidentally.

   Thanks for your time.