Vocaroo is a free service that allows users to create audio recordings without the need to install any software. You don't even have to create an account to use Vocaroo. All you need to provide is a microphone. I used the microphone built into my MacBook to make the recording below. To create a recording just go to Vocaroo.com, click record, grant Vocaroo access to your mic, and start talking. After completing your recording, Vocaroo gives you the choice to publish it or to scrap it and try again. Vocaroo provides the option to embed the recording anywhere. Vocaroo provides the embed code for you. You can also download your recording, just look for the download link at the bottom of the page (it's small and easily overlooked).
Audio Pal is a free service that allows you to quickly and easily record audio messages to post your blog or website. You can record your Audio Pal message by phone, through your computer's microphone, or by uploading a recording. Messages are limited to sixty seconds so you must be succinct. After you've recorded your message, Audio Pal will play it back to you. If you like the recording, keep it. If you don't like your recording, click re-record. When you have a recording with which you're happy, enter your email address and an embed code will be sent to you almost immediately.
Voki is a service that allows users to create animated audio avatars that they can embed into their wikis, blogs, and websites. Getting started using Voki might take you a little longer than using Audio Pal or Vocaroo, but you get the added benefit of having a talking avatar to draw attention to your message. For teachers interested in having their students use Voki to create messages, Voki does offer an ad-free version of their service for educators.