This is probably the 1001st post about this subject, but I can’t help thinking that some people actually give up on this. It is a simple protocol, simple program and should be simple to get working. I spent a few hours (!) before I finaly found the solution. I searched the internet but this answer never seems to be given on forums. I’ll try to be complete, so here it goes:
Configure iChat as described by Google. If you still can not connect, there is a good chance you have started the firewall on your mac, and it is blocking iChat. Open the system preferences, and in the “Internet and network” section select “Share”. You will notice a firewall tab in the middle. Select it, and make sure there is a thickmark next to “iChat Bonjour”, like in this screenshot:
(Sorry for the Dutch layout, I’m sure you’ll find it with this pointer.)
This action solved my iChat connection problem. I also installed Adium, which also had connection problems. The firewall setting solved the Adium problems aswell.
I’m not sure which chat client to choose. iChat is more integrated into OSX, and imported my google contacts without a problem. Adium did not import any contacts. I’m sticking to iChat for now, hoping that the integration with the rest of the system will give me some pleasant surprises.
Oh and yes, you’ve noticed correctly, I’ve bought a Mac. The desktop PC at home crashed one time too many.