Best way to do Wireless AutoSwitching

Please explain further. Are you trying to do SSID switching? Band switching? Vlan switching? iOS or OSX or both?

We created a solution using crankd from pymacadmin to switch automatically between internal and external network locations when the network changes.

This website contains an example of how to use crankd:
http://blog.hoachuck.biz/blog/2013/01/20/connect-microsoft-communicator-on-mac-os-when-network-status-change/

Crankd website:
https://code.google.com/p/pymacadmin/

Crankd supports several triggers like network changes, filesystem activity, application launching, etc.. Perhaps it fits for your needs too.

Ahh, sorry, I guess I left out some details :)

We want to turn off wifi when the lan is plugged in, and turn back on when the lan is unplugged.

That's been addressed several times in a few different scripts and threads. Just search here on JN for that. You'll find the answer.

I'll just say that be cautious about turning WiFi back on when Enet isn't plugged in. It was before my time at the company I'm working at, but I was told we had it working that way once but mobile users that traveled a lot with their laptops found they couldn't turn wireless off when on plane flights, which was problematic. The Launchd/Script combo kept seeing that Ethernet wasn't active and would turn WiFi back on. I'm sure that can be addressed with some additional scripting, but just be aware of that.