Is there a way to include native libraries in a JAR, like in Java Webstart, without using Webstart?

Question

I'm working on a game that uses LWJGL and thus requires native libraries specific to each platform. On this page, the author shows how to use the <nativelib> tag with Java Webstart to include JARs containing the appropriate native libraries. I'm trying to do something similar, but without using Webstart.

I tried adding the native library JARs to my main executable JAR's classpath, but that didn't work. Currently, the native libraries just sit in the same directory as the main JAR and that works fine, but I'd like to make it a bit tidier.