Real Movie to AVI
Tinra has been of limited success for me, I have had some issues with the audio going out of synch totally. Most of the time I could recover from this, but the process is not easy, or quick.
Tinragui is a UI for Windows which makes tinra a little easier to use. You can download it from here (291K).
I really dont know how well this works with the newest version of Real Player though.