Aimed at devotees of "soul sports" like surfing and diving, the newly opened Camp in Costa Mesa, California, is made up of specialty stores that offer an interactive take on the mall experience. Want to see how well that underwater camera really works?Jump in the 11-foot-deep pool for a test dive at Liburdi's Scuba Center. Torn between two surfboards?See how they float on Billabong's pool. If you're thinking of a weekend camping expedition, Adventure 16's map machine will help you choose a destination; a staff expert will figure out your gear needs. To complete your alternative shopping trip, the parklike mall has a Bikram yoga center, two restaurants, and an outdoor fire pit where athletes, health gurus, and environmentalists make regular presentations. The Camp, 2937 Bristol St., Costa Mesa, Calif.; 714/444-4267;