I went to Peru and Chile last October, and found the weather all over both countries wonderful. The north of Chile (I was only in Arica and then flew south) is indeed a dry desert, but the city is pleasant enough, if boring, and the seafood is great. The idea was to take as many trains as possible, but unfortunately no passenger trains run to Arica anymore. The La Paz train disappeared decades ago, and the one from Arequipa only runs now and then (no one could tell me when), so I crossed the border in a "colectivo," which was efficient enough. The train from Puno to Arequipa, in Peru, by the way, ran through some pretty dramatic and interesting countryside. I also wanted to take the ancient sleeping car in the train from Temuco to Santiago, and I recommend it only for hard-core train buffs. Chile is a vibrant, successful country, so enjoy yourself.
By the way, Chile charges Americans about US$60 for a visa (about what the US charges Chileans), but Europeans can get in for free.

[This message has been edited by Track (edited 10-09-2002).]