Skype is having problems today.  Clients are crashing, or logging out, or refusing to log in.  We use Skype chat a lot.  The persistent chat streams are great for running multiple conversations at one time.  For today, we switched our teams to the Assembla chat tool.  This is better for keeping the team focused on one task and on project activity, so it has a different effect.  You can add a chat tool from the space Admin tab.