I've got quite a handful going. Not so much mood boards as actual inspiration boards for things I want to include. Magnagorans might recognise the below:
They have to be online, yes. Having to chase people down with arrows was not ideal so we cut that part out but the other person should still be online.
It's lovely. My use is not super imaginative but, aside from the chat window, the other window is a tab-palooza for all sorts of debugs, events, alerts, etc.