Can anyone recommend an easy to use Flash animator tool for MacOS x that would be suitable for creating a simple web banner ad?

A graphic design friend of mine has a mac and has been asked to create a simple banner ad for one of his clients. The ad has a jpeg background and some animated text in the foreground, and will of course need to link to a web site (getURL). Flash solution is probably best because the client's file size requirements are less than 40k and gif animation is not suitable due to jpeg content.

He does not have a copy of Adobe Flash authoring software and since he uses an older non-intel mac and is not able to download and try out the CS5 suite. Apparently CS5 is for intel macs only at this time.

Any recommendations much appreciated.