I just added a voicemail feature for easier commenting. See that little "Send Voicemail" popup-bar on the far right there? (It takes a few seconds to load)
Just click it, make sure your mic is on, then click "start recording." Be sure to hit "send" when you're done!
More importantly, wouldn't that be a great addition to your library site? A great way to get student feedback/comments. Of course, if you hosted in on Wordpress.com you're out of luck. Most add-ons don't work with that, though you can add a link.
To get the addon from Speakpipe, click here.