Chat Software Help

Hello, I just bought my first mac and it should arrive to me here shortly. I'm currently in Iraq and all i will have is the mac. My wife at home has a windows based laptop. Is there any chat software that we both can download or something that will work on Mac & Windows? Sorry if this is a newb question but it's my first mac

You can use just about any network that you can on Windows including MSN, AIM, Yahoo and ICQ. If you want access to all, I suggest Adium. On Windows, you can download each respective client or an all in one like Pidgin.

ok thanks for the help, i'll have to save this for when i get the macbook.

And what would be the answer for chat with audio and video?? I've read all programs stating this, just doesn't work...

Skype or Yahoo messenger have worked well for A/V for me in the past.