before i got spinervals videos i taped the tour de france to watch during my training.
sometimes i just get into a zone with a regular t.v. program and do intervals to the commercials.
i have also watched a sporting event (basketball for instance) and rode race pace during the action and did an interval when there was a free throw or t.o.
football lends itself to intervals as well.
the best training ever though is good music and a completely pitch black room that zero's out your senses. i loved that way the best.
mix it up. the mental burn is the worst burn of all.