See this article:
Everything you may need to know about sound recording on the Pocket PC
(the name is quite appropriate)
and especially the section named "Sound quality", where several products are listed.
EDIT
More specific solutions are commercial in nature. Here are two that got good reviews:
ViTo SoundExplorer ($7) with a review here that concluded:
Being an audiophile, SoundExplorer
turned out to be quite a treat for me.
It has each and every feature I could
think about and those too that I had
only imagined. I haven't seen anything
as advanced as SoundExplorer for
Windows Mobile.
It not only has excellent playback
capabilities but is definitely the
best recording solution that is
available for WinMo users. I could not
only record voice memos easily but was
also able to add bookmarks to these,
not to mention its Voice Activated
System that allowed me to initialize
and stop the recording procedure
automatically when sound ambience was
at a certain level.
I also think that it is very
reasonably priced at $7.00,
considering the usability and loads of
features it has to offer. I used the
application for more than five days
and could not find anything negative
to talk about and ultimately ended up
buying the paid version.
Resco Audio Recorder ($24.95) with a review here that concludes:
Having put this program through its paces, I believe that Resco’s Audio Recorder does pretty much as advertised. I
found it to be an excellent recorder that took some of the complexity of choosing a format and bit quality down a notch
for an average user (like me) but I could also see if you were a power-user, you would find all the necessary options
to make you satisfied too. The sound quality was very clear and the application well worth the price. Resco offers a
31-day trial so be sure to try it before you buy it!
