Articles by Wilfried Herget, et al, and Bernhard Kutzler at kutzler.com
Some serious thinking about technology in the classroom from Jenny Little.
A good book: Fey, James T. , Al Cuoco, Carolyn Kieran, Lin McMullin, and Rose Mary Zbiek, editors. Computer Algebra Systems in Secondary Mathematics Education. Published by the National Council of Teachers of Mathematics, Reston VA, 2003. Find it on-line.