Can someone help me find a replacement for Yammer?

[wonk]

Hi all,

I'm running a trial roll out of iPads in my company. I'd like the trial group to be able to chat with each other to share experiences and discoveries. We use Yammer as our corporate tool but it is clogged up with loads of irrelevant stuff.

Can anyone suggest an iPad app that could support the group discussion? I've looked around but found nothing so far.

Thanks,

Nick.