MacResearch

PeepCode is a small company dedicated to making high quality screencasts for the latest technologies in software. A lot of what they do centers on the web — lots of Ruby on Rails and Javascript — but they also cover some topics of interest to non-web developers, and even scientists. For example, they have just released a screencast covering the version control system Mercurial, which is used on Google Code and is steadily gaining traction. Other topics for which screencasts are available include MacRuby, how to screencast, controlling your email Inbox, Emacs, productivity for programmers, and the version control system Git.
The screencasts each cost $9, which is a very reasonable price, and for that you get around an hour of video in a variety of formats, including ones that will play on an iPod.