It appears that Google is having trouble with some of their services, including Gmail. Gmail did experience a complete outage, though Google says that service has been restored to several users, and now it, Google Documents, and Google Presentations users are seeing service disruptions. Google expects full service to be restored within the hour.
Some of us have taken to cutting and pasting email into IM as a work around. Reminds us how dependent we've all become on Google! Are you having trouble accessing Google Apps?