I'm going to Argentina for about 24 days during May. It will be late fall going into winter during that time, although for the most part the winter appears to be not terribly cold (lows in the 30s). I'm trying to figure out a reasonable amount of gear to take along both for outdoor activities such as climbing, hiking, camping, etc... as well as stuff that will serve me should I want to go to a nice restaurant and not look like a mountain climber.

Calculating the weight of all of my gear, I am verging on 35-40 pounds. Granted I will be wearing a good portion of that weight, but I was just wondering if any more experienced travel backpackers have some advice to help me lighten up.

Here is an idea of what I have

Pack and accessories - 15 pounds including:
main pack
daypack
pack cover for airport transit
pacsafe mesh security
compression sacks
sleeping bag
sleeping pad

Camping / General Gear - 9 pounds including:
stove and fuel bottle
mess kit, orikaso plate/cup, spork
nalgene and platypus
first aid kit
toothbrush and such
packtowel
digital slr w/ 2 lenses, 2 batteries, and charger
flashlight and extra batteries

Clothing - 12 lbs including:
boxers
wool socks
silk long underwear
capilene t shirt and midweight crew
merino midweight layer top and bottom
down vest
softshell top and bottom
waterproof / breathable shell
hiking boots
1 pr. nice casual clothing for not outdoor stuff