I've converted iwconfig to compile under dietlibc, find attached the EXE (70k). This is how it's done:
Obtain wireless_tools.29.tar.gz (Wireless tools, Google for it)
Substitute attached Makefile for dietlibc build of iwconfig
This turned out to be simpler than I first expected. You just have to define a couple of things to ensure gcc picks up the right definitions when run in the dietlibc header environment. I'm sure that the Makefile can be extended to compile other wireless tools - they all seem to depend on the iwlib.c file. Please note that this iwconfig is not tested other than to run it - it may not work properly!