Motebook is a time-saving feature available to all Unlimited tier users.
Here's a great introduction from Aish Dean.
Adding voice notes to your motebook
To add a voice note to your motebook, just click the 'Edit' button from an existing voice note 'card', or the Preview button when you create a new voice note.
Next click 'Save as ...' and then enter a name for your new voice note.
Hit 'return' or click 'Save' to save your voice note to your motebook.
Then click 'Exit' to leave the Edit mode.
Retrieving voice notes saved to motebook
Access your motebook by holding down the Mote 'M' button for about 1 second - there's a new tooltip that explains this (see below in Google Docs).
You'll then see your saved voice notes in your motebook menu.
You'll see a reminder of the text of your voice note when you hover over the motebook entry.
Click to select your voice note from your motebook, and a copy will be pasted into your comment box. You can then review the voice note using Preview, or just hit 'Comment' or 'Reply' to post.
Please note that motebook is only available to Unlimited tier users, and that there is a 100-mote limit.