I'm not sure of the different applications which may have this problem, but below is what I experienced when I downloaded and installed OpenOffice.org 2.1:
Downloaded and saved (no issues or problems)
Ran the setup program (no reported problems or issues)
Selected Start-->All Programs (NO OpenOffice)
I located the install in C:\Program Files\OpenOffice.org 2.1
There is a ton of directories and sub-directories, but I could not find an executable.
It's late so I decide to tackle it the next day.
Following day, I start to explore the new Vista and when I right click with my mouse on the desktop and select new I discover the OpenOffice - Document/Drawing/Text/Presentation/Spreadsheet Icons.
I select a Document and OpenOffice prompts me to register which I do. I create a dummy document and save it. However - As I later discovered the registering of the software allowed it to be visible from the Start-->All Programs menu.
OpenOffice is free to anyone who wants to use it and I think this is a really slick
way of gathering user registration. But some users will (as I almost did) remove the package.