Microsoft Recite — an easy way to remember, search and retrieve mental notes and reminders. To use Microsoft Recite, you must have a Windows Mobile powered smartphone.

Microsoft Recite Technology Preview makes a busy mobile lifestyle easier by providing an easy method for remembering, searching, and retrieving mental notes and reminders from their Windows Mobile® device using the sound of their voice. Without navigating menus or tapping out text just speak your mental note to store it. Later, when you need the information just search and retrieve the remembrance using your voice

Recite does not work on all phones so make sure that you check to see if your phone qualifies.

More info can be found here.