I downloaded SpringPad, but it's a little more than I wanted. I miss the old Palm platform (Centro), which allowed you attach notes to just about anything.
The Atrix is such an awesome phone but it does have little weird quirks like this. I am using Evernote now.
One of the other things that I think is odd is that the Clock application is only Alarm and Timer, no world time or stopwatch which I would consider pretty basic.
I have been very happy with Note Everything. I does Text notes, Paint notes, Voice notes. If you get the Pro version it allows: Photo notes, checklists, and Reminders.
It doesn't matter what apps come with the phone out of the box anymore. You can get anything you need from the android market. I use Evernote and its better than any note application I have ever used on any device out of the box.