K-nex were once a simple toy practically equal to finger painting, but the artistic part of K-nex is only so good. Models are cool but they don't do anything. Even though models are pretty interesting, practical uses for k-nex (or just functional k-nex contraptions) have a different consept entirely. From guns to...
http://stuarthughes.blogspot.com/knex-leg.jpg
Building for a purpose with a "mechanical" goal is always much more impressive than building something that looks like a dog or a snowflake or any other little insignifigant thing.