Linking the GBA and NDS together

It's been a while since the Nintendo DS where released, but still I havent heard abouth anyone who managed to communicate between the NDS and the GBA, or even link on GBA games with two NDS's.

I recently bought the NDS Lite (Have never had a NDS before), and what a difference it was when I inserted some of my old GBA games in it and plugged the power on. The GBA games have never looked any better!!!

What really suprises me, is that I still haven't found any accessories on the net that make the NDS communicate with the GBA (A NDS cart with an GBA EXT port, with the possibility to insert a GBA link cable in the NDS, or some kind of wireless wifi-to-GBA link-cable converter, an adaptor that recieves the signals from the NDS and transfer them to the GBA link cable).

Anyone know something I don't when it comes to the NDS-GBA connectivity area?