Sling TV, the streaming service that isn't quite a household name yet but is a very useful live on-demand alternative to cable, is offering a special deal this Sunday. Starting at 8 a.m. ET on Oct. 22, new users can take Sling for a free test drive, no credit card required. Just go to sling.com/watchfree and enter your email address. The Sling product being offered for the trial is Sling Orange, the basic tier which offers 28 live channels for $20 a month.