My copy of Adobe Illustrator CS (version 11) crashed today on startup. I traced the fault to a recent install of a trial version of Logitech's NuLOOQ software.
The solution was to remove the NuLOOQ folder in Illustrator's Plug-Ins folder. Logitech does list that only Adobe Creative Suite CS2 apps are fully supported by NuLOOQ, and only limited compatibility is provided for older versions.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20060224131857192