adjl posted... I always found that was a problem with any of the GBA-based multiplayer games. GBA connectivity was a neat idea that was always held back by the requirement to have friends with GBAs to take advantage of it. I had enough cables to connect everyone, and between replacing my base GBA with an SP and borrowing my sister's I was able to supply enough for my core group of three to play them, but that wasn't exactly ideal because the SP was clearly better than the other two. I think that concept suffered the same problem as Streetpass in that portable gaming is (or was) just bigger in Japan and it was therefore easier to find somebody else with the necessary systems.
It's an idea they could actually revisit a lot more effectively now. Almost everyone has a smartphone and consoles are already bluetooth-enabled, so if the individual content was just streamed to a phone app instead of needing to connect a dedicated handheld system, you could get that kind of asymmetric personal view with just about anyone. Controlling it might not be ideal (though recreating GBA controls on a phone isn't terribly hard), but it'd at least be more accessible and require fewer extra peripherals than the GBA connectivity idea.
People are doing pretty cool workarounds with emulators these days for Crystal Chronicles. The setup was so ridiculous. My friends and I did it a fair bit but it still required planning, and was later in highschool years, not when the games had initially come out.