I have a problem with the term "must have". if i must have something it doesn't mean you must have it too. Except death.

If you must have an app another person must have, do you really have to have it? Do you really use it like the person who must have it?

If you must check out the N900's capabilities, just have a look at the repositories, they're all "must have" apps in some way. It's not as if we have 20,000 Android apps to chose from. It depends on the person and usage habits.