What I do is create a new, blank presentation called Test, and save it in a
folder called test. I open up Test and the presentation in question, and then
go to Window and arrange them vertically. Adjust the powerpoint window so it
doesn't go all the way to the bottom of the screen - at that bottom of the
screen bring up the Test folder in detail view. Drag your suspect slides
individually over to the test presentation, then hit save. Look in your test
folder, and you'll see the file size of that particular slide.
There's variations of this, of course. I'm working on 100+ slide
presentations, so I drag ten slides or so over at a time, and see if any of
them are huge. When I find a huge slide, I'll start removing graphics
one-by-one until I find the culprit.
Also go to File, Properties and it will tell you if there's an embedded
object (just not where). It'll also tell you the fonts used - sometimes there
can get to be some weird fonts in presentations.
Be sure to turn off Fast Saves, that'll bloat the presentation.
It doesn't hurt to (one a scratch copy of the presentation) to delete all of
the slides and see the file size. I've seen ones with no slides that are
still 10Mb or more. I just discovered a master slide the other day that had
an embedded link (but with no object..I had to select all, then de-select all
of the visible elements, then go to the linked object) to a three year old
presentation.
