You’ll need Pro to do the portal effect correctly (using RenderTextures) but otherwise a simple transporter script will work. Look at moving the player’s Transform to the exit portal when you hit a trigger on the entrance portal. If you go through the scripting tutorials you should get the hang of it pretty quickly, its really not that difficult.
The project folder for portals is here. I’ve been meaning to change my contribution and let a few people know about it, but things are just too busy right now:
Basically my idea of dragging ragdolls with the mouse, and having a mouselook on the camera at the same time is a non starter. I didnt really do this project justice, but at the time I didnt know much about unity.
It was built with Unity1.6 theres been a few shaderlab changes since then. That may be the issue. Make sure theres no unassigned slots in the inspector, and are there any errors or warnings in the console?