Michael Steeleworthy posts his opinions on Camtasia vs. Captivate vs. the Organization. I'm not sure where the Organization part comes in, but he makes some interesting points about why he gives Captivate a nod over Camtasia. Personally, I don't care about the file size, which seems to be his biggest concern with Camtasia, 'cause I recommend hosting the output on YouTube, which offloads that issue to their servers.
Over on Issues in Science and Technology Librarianship, Olivia Bautista Sparks has an article called Five Minute Screencasts -- The Super Tool for Science and Engineering Librarians, which of course is useful to all librarians. In addition to providing links and tips, she has several short examples of screencasts she's built for orientations, reference consultations, class instruction, and full instruction loads. Also check out her LibGuide on screencasting at http://libguides.asu.edu/screencast. All of the tools she examines are freebies.
I believe I owe thanks to Stephen Francoeur's shared Google News items for both of these links.