With its finger on the pulse of L.A.'s anxiety, Ben & Jerry's Howard Hughes Scoop Shop is trying to chill everyone out before Carmageddon with free ice cream today. From 4:00-6:00 P.M. this evening, the Vermont ice cream pushers will give out free scoops of the recently introduced flavor "What a Cluster," a peanut butter ice cream with marshmallow swirls, caramel clusters, and peanut butter. Now you must decide. Are those magic words "free ice cream" tempting enough to get you off the 405 as you race to beat the 7:00 P.M. cut-off time? Or is buying a $3.50 pint going to be the best money you ever spent tonight? 4:00 to 6:00 P.M. at Promenade at Howard Hughes Center.