While we are talking about Syncdata's latest SmartphoneNotes version, eBook Software recently released PocketNotes for Windows Mobile Smartphones which basically do the same - creating and viewing Outlook Notes.
With PocketNotes you can also create and categorize your personal and business notes as well associate notes with colors and categories.
However, unlike SmartphoneNotes, which you can simply synchronize with your PC via ActiveSync (Syncdata spend most of the time to make this working because it's not that trivial), PocketNotes can import/export the Notes from/to Microsoft Outlook only.
PocketNotes is available from Handango for US$ 14.95 and doesn't includes a trial version yet.
Cheers ~ Arne