Other effective approaches to traffic minimization are:
1) content filtering (less connections are established and less data are downloaded)
2) improved caching
First could be done in different ways with a number of tools:
- filtering DNS servers (OpenDNS, FoolDNS, NortonDNS etc.) It seems to me that
FoolDNS is the simpliest one with good filtering out all the scam (ads, trackes, webbugs, malwartizing);
- adblocking tools.
AdBlock Plus and
Privoxy are 2 of them already adapted for KM;
- fine tuned filtering on the domain-level - with
ExExceptions (yes, this FF addon works with KM fine) or native
Blockeria macro by
siria;
- sure you can switch off JS, images and block Flash with KM in-built options;
- using mobile or touch site-versions where possible. For example m.facebook.com is way more lightweight than main version.
For second goal you can use portable local caching server
HandyCache for example.