From here: http://support.apple.com/kb/ht2396
Transferring a recording to a computer
Voice memos are saved in a Recordings folder on iPod in the WAV file format. If you enable iPod for disk use, you can drag voice memos from the folder to copy them.
If iPod is set to update songs automatically and you record voice memos, the voice memos are automatically downloaded to a playlist in iTunes when you connect iPod. Once downloaded, the voice memos are removed from the Voice Memos folder on your iPod. To play the voice memos that have been synchronized to your computer in iTunes, select the Voice Memos playlist on the left side of the iTunes window. To play the synchronized voice memos on the iPod, select the Voice Memos playlist in the Music menu, not the Voice Memos menu in the Extras menu.