Top Hollywood Agent David knows better than anyone how to deal with Temperamental Talent ... but when it comes to negotiating with his Gigantic Newfoundland Retriever, Riptide, he could use some lessons from the Dog Whisperer. The Dynamic Duo made the scene this morning at 7th and Montana and, as usual, Riptide "refused" to leave. For the record, Riptide weighs-in at 170-pounds. When he wants to stay put, he simply "plunks" himself down for the duration. Last week, David had to "bribe" the Precocious Pooch with a Large Frozen Yogurt just to get him to move. Today, however, he resorted to more Desperate Measures: He called his Assistant who, moments later, pulled up in a Lexus to bring the dog home in True Hollywood Style ...!