BOCA RATON— In the muddled aftermath of Election 2000, Lawrence Caplan lost a legal fight and learned an important political lesson at the hands of none other than Vice President Dick Cheney: You can live in one state and vote in another. Caplan, a tax and corporate lawyer, has turned that lesson into Operation: Snowbird, an Internet tool designed to make a difference in the election of 2004 — if Democratic voters in New York and New Jersey respond to it. POPULAR PAGESAll they have to do, according to Caplan's Web site, www.operationsnowbird.com, is switch their registrations to Florida, where...