Go to the closest Asian shop and find a kiwi knife, there's usually quite a range, they're spring steel and very light. They're under 10 bucks, maybe under 5 in bigger cities. Some people would consider them disposable knives but they sharpen up wonderfully. The blade is so thin they actually cut well even when dull.
I just checked mine, the most common size santoku and it's 82 grams, 17.5cm blade and 28.5cm overall. The more commonly have wooden handles.
Gadgetgeek wrote:I've been trying to get my hands on one of the MSR alpines
I have a friend with one and I don't think they're much good. They chip really easily. I've carried a victorinox paring knife which would be similar weight and slightly smaller, but much better blade and half the price.