If you are coming down with a notebook, bring an ethernet cable also, they have hookups here in 155, hotel cal and the coffee house but no cables to hook with.
You may also think about bringing down extra shoelaces or bootlaces as they suffer badly here with the dry and wind as well as volcanic dust. MP3 players are standard for most and a battery charger may be useful also but you can usually borrow one from someone already here. Slippers for the lounge or dorm room as well as something to relax in for your off time and if you are working outdoors a bit you may want to bring a sweatshirt with an attached hood which will allow you to store gloves in the pocket and keeep the wind off your head but not be too bulky later in the season when it gets warm enough to walk around in such, many of us do and some are crazy enough to walk around in shorts. Be careful of power cables, they tend to do badly with the dryness here so handle them nicely. Theres more things also but thats teh most important of things to bring with you.