I have been playing with Virtual Breadboard for about 30 minutes now. It is very cool for the price (free). I have not gotten this far yet, but it looks like it can do many of the things a $$$ simulator can. I am not saying it is as good, just saying that so far, looks like it is worth it's free price many times over.

Here is a video of a few things that can be done with it.
http://www.virtualbreadboard.com/vid...EX/RunHex.html

Site: http://www.virtualbreadboard.net/Hom...8/Default.aspx