Ever since I grabbed my GB Micro from Amazon.com because of a price mistake, I have had a hard time putting it down since. I showed Matt when he was over the functionalities of it; a unit abotu the size of an NES controller that I was playing old skool Legend of Zelda on, so in other words, I love it. Keeps me entertained..however…Nintendo isnt putting that much into accessories. Granted, I have a GBA SP, but it’s been sitting in a drawer since I grabbed this thing, and I was looking for a cable to hook up the GB Micro to my Game Cube (I have a series of games that utilize the interface between the two units)
…Nintendo doesnt make one. I was sad. …. Until I came across this:
http://www.cheapassgamer.com/forums/showthread.php?t=79849
Woo! So, I ordered the parts from Nintendo (along with a all-black faceplate) and It arrived at my house today. I’ll be doign some soldering at work on Thur, getting this to work….and tossing my GBA SP up for sale.
But wait! you cant play GB or GBC games on the GBA Micro! Stop!
I sure can. I know of a way. 
When i get the project completed, I will post a picture.