Ever since I first heard about it, I have wanted to go to NAMM and see all the fascinating things that people/companies come up with. I get the idea that the large manufacturers are there in force, as in many other trade-shows, and there are a lot of smaller startups etc. that also show up.
I found a temporary solution this year though–NAMM Oddities. Barry Wood has done an excellent job of compiling some of the more interesting/offbeat things he ran across at the show.
Theses finds range from the absolutely fascinating, to the just plain odd. There are pictures, and videos available. He also provides links to the home pages of the respective companies. Great site.
Also of note is the O'Reilly story along the same lines (in fact, it was inspired by the page referenced above).