Create a Live internet Radio Show Free
Limitations: allows you to record shows and episodes for a maximum of 30 minutes for each recording (it isn't a limit per day, but it refers to a single produced episode); There is no limit for uploaded podcast durations. You'll also have 20 hours worth of audio storage, which include all tracks uploaded as well as the podcasts you record.
Virtual classroom with whiteboard, text chat, audio chat. You can upload images to the whiteboard, draw, and enter text. No registration required. Words on iPads as well as web browsers.
Limitations: No video chat. No option to upload a PPT or PDF.
Used the online editor to crop videos from YouTube, KhanAcademy, and other sites. Then record audio directly in the browser, and add multiple-choice and open-ended questions at any points in the video. You can also add audio notes. Useful for flipping the classroom.
Limitations: You can't upload your own videos to the site. However, you could upload them to YouTube, then access them through EDpuzzle.
Video lessons on a wide range of subjects, aligned to Common Core. Seem to currently (as of 5/12/2013) have no language lessons. However, you can use this as a repository to upload your own lessons and share them.
Simple online voice recorder. Share your recording via email or embed. Alternatively, you can upload a file. Recordings can be downloaded. No registration required.
Upload a PDF and add video, images, audio, comments, and quizzes. (You can also annotate using a pen, but only you will see those annotations.) You can also create classes and add the PDFs and students to them.
Limitations: With the free account, you cannot make a document private.
Upload an audio file and transcribe in the browser. Keyboard commands so that you don't have to move your hands to pause, rewind, fast forward, and adjust playback speed. Also has a command to insert current timestamp. Learners could use this to check their detailed comprehension of a listening text. Also useful to researchers with audio recordings to transcribe.