I wrote this simple swf encryption tool.
It can pack your swf into a packer/shell to prevent your swf being decompiled directly.
Only as3 is supported.
SWF Cry is in a very primary status now (v0.02) but it works!
Try it here (my blog post with instructions):
http://bruce-lab.blogspot.com/2010/0...-your-swf.html