How to share my Snow Leopard Mac's connection to my HTC Desire running Android?
OK so you need to connect to the internet via your MacBook to get around a MAC filter on your router.  You can share your MacBooks connection but it would need to be plugged into the router.

I don't think it's possible to do it like this:

HTC >> WiFi >> MacBook >> WiFi >> router

You need to do it like this instead:

HTC >> WiFi >> MacBook >> Ethernet >> router

So you plug the MacBook into the router and connect to that from your phone over WiFi.  You can do this as follows:


Choose Apple > System Preferences, and then click Sharing.
Select Internet Sharing.
Choose a network service from the “Share your connection from” pop-up menu, Ethernet for example in your case.
Select a networking service to share your Internet connection from the “To computers using” list, AirPort for example.
Click AirPort Options and give your network a name and password.
Connect to your MacBook over the WiFi network you just set up.