@tt_su said:
We're actually working on a Hello World example for Visual Studio and Xcode for compiling Ruby C/C++ Extensions for SketchUp. We can expand that (create a work or extra branch) with SLAPI configured as well.
By the way can you post a Gist of your code? You got some syntax errors there that appear to not be related to linking to the correct headers.
Interesting, I was just now doing some research into 'extconf.rb' and I'm starting to think my problem is related to not configuring the location of the .lib and .h files inside of 'extconf.rb' using the 'dir_config' and 'have_library' commands.
BTW, the only difference between my code and your 'hello world' code on bitbucket is that I #included one the SLAPI .h files at the top.
I had assumed (or hoped) that it would be properly linked since I put the files in the same location as the .c file that I was trying to compile. 
It goes without saying that I am a complete noob at this.