KST chat

Personally, I find this very useful. 

When I remember, I share my current 8m activity so people know where to watch for me. 8m activity is on the 50 and 70 MHz chats.

I see others use it to arrange skeds.

See http://www.on4kst.info/chat/index.php .

ON4KST chat

See http://www.on4kst.com/chat/start.php . This is probably the most well used chat facility for radio amateurs on the internet. It is set up with various "rooms". People tend to use it to arrange skeds from VLF to microwaves.

ON4KST chat for skeds

Quite a few people us this to arrange skeds on VHF, UHF and microwaves. It is also used for some LF/MF skeds too. There are different forums for different bands.

See http://www.on4kst.com/chat/start.php .