User interactivity (Flash/PHP/MySQL Integration) [MX]

Hello
I've been wondering how to create something for users to interact with eachother

I know quite alot about MySQL and PHP and can make users interact with that but my side with actionscript integration is a bit puzzled

I used a tutorial to make a flash chat room with the integration which was pretty simple and I followed it rather well but how would I make users interact with each other in other ways..

Can someone please give me a simple tutorial for this like being able to see a user move around using keypress function like..

User = Circle graphic MC and can move around with arrow keys (keypress) and can see other users as circles too on the stage

(I know how to do keypress and movieclips etc, just puzzled on how to make users able to see eachother)

I just need that tutorial for seeing other users move around


I am planning on making a game with a little chatbox so you can chat and play the game with other users too.
I'd also like to know how to save users data with MySQL.. like current position on stage and current score etc
I do not want it to save the user automatically, I want a save button for the user to use if they want to save


This game will start out very basic with basic design as I do not yet understand the user to user interactivity much yet.. But once I know more I can make it more advanced

Thanks in advance
Karl