I got the idea from Ben's pirate famicom thing. They took apart the Ique on lik-sang and it's basically an N64 on two chips. This might make a really small N64 portable. You would have to do a good amount of hacking it but it would be wroth it in the end to have a super small N64 portable. What do you guys think? I couldn't find the link please post it if you can find it.
Check lik-sang.com for it but it's basically an N64 in a controller. They have these specially developed cards for it that are the games. It's about the size of an original xbox controller.
Here I found the link: http://www.lik-sang.com/news.php?artc=3214
Inside the game cartridges is a 48 pin tsop chip. You could maybe make the cartridge into a normal game. You could do some hacking if they're not the same. They have to be somewhat simialiar though.
From the look of the sys tem, you might need to do some rom flashing and patching for it to work, or a big adaper.
Also I read somewhere that they weren't sure it had the full v-ram to run expantion pack games like DK 64.