Until this year, summer park-hopping sure sapped a lot of green. An ambitious seven-park circuit - say, starting at Joshua Tree, looping through the Grand Canyon, Bryce, Zion, the Grand Tetons, and Yellowstone, and winding up (exhausted but invigorated) at Glacier - could set you back $110 in entrance fees. But with the new National Parks Pass, introduced last month, visitors can blaze the same happy trail for only $50. The pass is good for a full year and accepted at all 379 national parks, from Florida's Everglades to Hawaii's Haleakala. Pick one up at any park entrance or on the Web at, or call 888/467-2757.