Acrobat Reader just stole about 5 minutes of my life. I opened a .pdf file from the web and IE froze. I waited and $#!$%"# then I realized Adobe is notifying me there are no updates to the Reader in a window below IEs window. Thanks, Adobe! I needed that information badly! (Window had only OK button. Only way to make this even more annyoing would be if Reader would ask me: "Do you want to do nothing, since there are no updates? Yes/No")
I googled for speed up trick I read about some time ago and I found out the trick got even better in the mean time! It looks like Adobe now officially supports the trick of hiding plug-in files. There is a new "optional" folder and there is even readme.txt file in there that says "Put unused plug-ins in the optional directory."
So, just move all files from Plug_ins (in \Program Files\Adobe\Acrobat 6.0\Reader\) folder to Optional folder and it should work just fine.
I found the trick update on Darrell's blog.