freehand or illustrator. they both work pretty much the same. if you know one you can use the other with a little digging around. freehand and flash are made by the same company so compatiblity is better. but thats just getting the elements into flash. you can do it with illustrator as well by exporting your file to an swf file that you can import into flash. i like illustrator. i think its an app that is well taken care of. a lot of people use it. however i know a few that only use freehand. but either way, whatever you choose isnt going to hinder your development with flash. they both work fine.