Vocaroo is a free site that allows you to make voice recordings. Plug in your microphone and click "Record". That's it.
Once your are done recording, you can listen to it and then save it. You can embed the files in a site, share them on Facebook and Twitter (among others) and save as an MP3, Ogg, FLAC or WAV file.
This could be a great way to record voice podcasts for student review, or even have students record their voices for language and speech class.