Card sorting tools

Online and offline applications for the card sorting technique for usability and information architecture.

http://www.measuringuserexperience.com/CardSorting/index.htm
http://rosenfeldmedia.com/books/cardsorting/blog/card_sorting_software_tools/
http://websort.net/
http://www.optimalworkshop.com/optimalsort.htm
http://www.rosenfeldmedia.com/books/cardsorting/blog/card_sort_analysis_spreadsheet/
http://www.stcsig.org/usability/topics/cardsorting.html
http://rashmisinha.com/2005/02/24/card-sorting-analysis-one-size-fits-all-approach/ (comments alternate analysis methods)

Some of them are free for small online samples.