If you happen to have a TV or device with an analog tuner you have two choices. You can buy a converter box and possibly use a government issued coupon to get a discount or you can replace the old analog-based TV with a brand new digital one.
A converter box will most likely be the cheapest solution, but you'll have another remote to deal with. Some DTV converter boxes are already available like the Insignia Digital to Analog Converter Box which costs around $60. The federal government is offering $40 coupons that consumers can use on a basic converter box. You can request up to two coupons per household now through March 31, 2009.