Cogent, one of the worlds biggest backbones is suffering some network outage that is causing multiple different Internet issues. One such issues are latency to your site. Please refer to this forum posting.
http://community.discountasp.net/threads/internet-problems-today.23338/
http://status.cogentco.com/
http://community.discountasp.net/threads/internet-problems-today.23338/
http://status.cogentco.com/