(I take ABSOLUTELY NO credit for the creation / production / development of Phun. All rights go to their respective owners. I am merely a purveyor of knowledge)
Step 1: Downloading and Installing...
Windows XP and Earlier: http://www.phunland.com/download/Phun_beta_4_22_win32.exe
Windows Vista: http://www.phunland.com/download/Phun_beta_4_22_win32.zip
Linux (Wonder how many people will click this?): http://www.phunland.com/download/Phun_beta_4_22_linux32.tar.bz2
Once you have these downloaded, run and install them. It's incredibly self explanatory, so I won't bother with that. If there are any Technical fails check the phun site at: http://www.phun.at
Step 2: Now Open Up Phun!
Then after a few seconds of dialog, the Screen you hold dearly will appear! :D
Step 3: What Can You Do?
Brush - Draw a Polygon (Shape) and it will appear. Presto.
Drag - Fairly Useless. Use this to move around active objects.
Plane - Very useful. Creates a 'floor' for everything to happen on. Gotta have some ground to stand on, hmm?
Circle - Creates a Circle. Yes.
Box - Creates a Box. Yes.
Chain - Quite an Interesting tool. It creates a chain of circles linked by Hinges.
Springs - I find these quite useful for holding things together. Do with them what you will.
Fixate - Makes an object invariably stay in one place whilst running. Simply select this tool and click on which object you want to stop moving, fixated objects are marked with a X
Hinge - You know how a real Hinge works right? *Sigh* But ALSO, right clicking the hinge of an object can grant you access to Motors, which unlock a whole host of Phun things to do! (Get experimental, i'm not spoon feeding you everything!)
Play / Pause - Runs & Pauses your current scene. Easy
Undo & Redo - Most helpful things in existence. Be wary, they dont go back forever!
Mess around with these!
Step 4: Congratulations!
Thank you for reading this Instructable, I hope it has been enlightening. And as i've said before, don't be too reliant on this, get experimenting! You'll be surprised what you can do. To check out what other Phun users have done go to http://www.phun.at and check out the Phunbox!