The Atacama Desert is a wild and wonderful place, but outside of the aformentioned activities, there are not a lot of things to do. I have spent a lot of time working in and around the large copper mines in southern Peru and suggest, if you are looking for something a bit different, to head up into Peru. After spending a couple of days in northern Chile you might might want to head up to Tacna (in Peru about 30 km north of Arica) and catch a flight to Arequipa (LanPeru) that takes about 30 minutes. There are a multitude of things to do in and around Peru's second largest city - Colca Canyon excursions, wildlife refuges, etc. Arequipa itself is actually a rather interesting place as well with some good shoping, decent hotels, restaurants and interesting sites. The city has an old Spanish look and feel to it with an interesting plaza area.