Google Talk: It's great but..

My work group is loving this, because we can use it talk and send files across lots of people, with different IM systems. But there is only one problem. Some of us are on macs, in fact the ones who tried this out first. In order to get all the windows people on it, we've had to go back to a windows person with Talk installed as an application, which has the only way to invite people who are not yet on Google Talk. If you are a mac user, you have to use a mac client with jabber support, but then you have no way to invite more people to use Google Talk, that we can find, and the Talk help section points to the windows Talk application in order to invite more people.

Very frustrating.