Neoflash, makers of many popular backup units, flash cards or mod chips, are currently working on a N64 unit called NEO64.
* Supports ALL N64 console,all in one solution!
* Supports Multi-Roms, use menu to select the game on your TV screen
* Support SRAM save function
* Use USB linker to burn, very easy and fast to download the files
* Flash size from 128Mb up to 1Gb
More info in this thread.