1In small bowl, mix tomatoes and water; let stand 30 minutes. Drain thoroughly.
2In 3-cup microwavable ceramic fondue pot, mix tomatoes, cheeses, sour cream and onions. Microwave uncovered on Medium 3 minutes, stirring every minute, until cheese is melted.
3Place fondue pot on stand with candle to keep dip warm. Serve dip with assorted vegetables or baguette slices.