These are my favourites:
1. I use FreeConferencePro for phone calls. It is a free service, but each person pays their own long distance charges. This service allows you to record a call and then distribute it as an MP3 after the session. (If you have a lot of conversation in the webinar, you may want to do some editing… and obviously ask for permission to do so at the beginning of the session.)
2. Team Viewer is a free (no download of software) screen-sharing tool. You can talk with your webinar attendees on the phone (#1 above), while walking them through your PPT slides real-time.
3. I am using Screenr to create online training videos for free. The limit is 5 minutes, but most teaching modules are better as 5 minute soundbites, anyway. Tom Kulmann shows you how to convert a PowerPoint presentation into a video… without all the heartache. Go to his site at – http://learningppt.com/category/multimedia/video-multimedia/ – and watch his recent posts for the how-to’s. (I found Tom only a few days ago, and am just about ready to ask him to marry me, since I was having so much trouble with the quality of converted PowerPoint slides. Screenr creates sweet and clean videos, which are uploaded to YouTube with one click.) (I just bought my headset today for the voice over!)