I'm not a parent nor do I have experience with parenting groups and such, but you could try to get them to download a program called Skype. You can have large audio and text conversations on it. Download it for free (only pay if you call computer to phone). But, can only do video to video with 1 person at a time, so audio and text would be good. Free for computer to computer calls.

Or, try stickam.com. It's a site where you can have video, audio and text chats, although maximum for video I think is.. 8 or 10. That requires no installation, unless you need to update the software. You can make a private room on it password protected.

There's also yahoo, MSN, etc.. .