I use to have a program called dragon I beleive 
that just did that. A lot of image software now 
has that capability. I have photodraw, an older 
version, and it has the button (under web 
effects). 

Here is a link to a free trial offer from one 
distributor: http://www.ulead.com/ga/runme.htm

http://www.web-animator.com/ This one was a free 
on-line trial (left hand corner in orange box). 
It looks really easy to use.