On-line training is a relatively new field in education technologies that enables students to gain knowledge about to the latest achievements in the area(s) under consideration without leaving their home (or workplace).
Although, currently, the companies providing on-line courses are not numerous, they still exist. For example, the SANS Institute provides training with its "Intrusion Detection In Depth" course (http://www.sans.org/onlinetraining/track3.php), which allows you to become certified at the GIAC training center (http://www.giac.org) and obtain GIAC Certified Intrusion Analyst status.