Myna is a free web-based audio track mixer created by Aviary. Using Myna you can mix together up to ten tracks to create your own audio files. The sounds you mix can come from the Myna library, your vocal recordings made with Myna's recorder, or audio tracks that you upload to your Myna account. The video embedded below provides a great overview of the many features offered by Myna.
MyPodcast.com is the podcast service that the guys at Wicked Decent Learning used to use to share their awesome podcast with the world. MyPodcast.com provides free podcast hosting as well as free podcast recording software. (The software is available for PC only). I tested out the software in August and found it to be more than adequate for creating vocal podcasts. For schools that do not use Apple computers (Garage Band is standard on Mac) MyPodcast.com is a very good, free podcasting tool.
Pod Bean is the free podcast hosting service that I used to host all of my Free Technology For Teachers podcasts (I haven't made any since last fall). Pod Bean is a hosting service, not a recording service so you will have to use a recording program and then upload to PodBean to share your episodes. What I like about Pod Bean is the speed of uploading and the ease of integration with blogging platforms.
Blubrry, like Pod Bean, is a podcast hosting service. To record your podcast you will have to record it using Audacity, Garage Band, or another recording tool. Blubrry has a very detailed guide for first-time podcasters. They also offer Blubrry University which is a forum for finding help with glitches and problems you may run into.