For a wide selection of beachwear, local crafts, cheesy souvenirs, and batik clothing, try Boutique Coco Miko or Boutique Bambata, which are both on the main road near the entrance to the park. The latter is also a good place to have your hair wrapped in colorful threads and strung with beads. Out toward Playa Negra, similar wares are offered at the Cahuita Tours gift shop. Handmade jewelry and crafts are sold by local and itinerant artisans in makeshift stands near the park entrance.
Ask around town for a copy of Paula Palmer's What Happen: A Folk-History of Costa Rica's Talamanca Coast (Zona Tropical; 2005). The book is a history of the region based on interviews with many of the area's oldest residents. Much of it is in the traditional Creole language, from which the title is taken. It makes fun and interesting reading, and you just might bump into someone mentioned in the book.
If you are interested in the local music scene, pick up a disc by Walter "Gavitt" Ferguson. The local 87-year-old calypso singer and songwriter is a living legend and has two CDs of original songs, Babylon and Dr. Bombodee. Ask around town and you should be able to find a copy. If you're lucky, you might even bump into Gavitt.