Setup local network on Mac and share it via WiFi, but with no internet connection I woat to use my iPhone as remote control for VLC. I use http://hobbyistsoftware.com/VLC-more and it is working fine when I am connected to my AirPort network.

I will use my MacBook at a place where there is no AirPort connection (even currently is not available) for playing videos.

Is it possible and if so how do I run my mac as default gateway and access point but just for local network so that I can connect my iPhone to it ?

Thanks in advance
If you have WiFi turned on then you have a pizza slice icon at the right of the menu bar. If it isn't there then open Network in System Preferences to make sure WiFi is on and you have Show Wi-Fi status in menu bar selected.

Select Create Network... which will open up a dialog where you can specify a network name and security. I usually change security to 40-bit WEP just so the link is secure.

You can now connect to this network from your iPhone in the same way as any other WiFi net.