Yes, there is one called Neo N64 Myth Cart. It seems to have good compatibility, but costs $200. Not to mention it doesn't use standard storage media either... I really wish there were SD/Micro SD versions of these carts. I'd have one for all of my consoles!
http://gbatemp.net/t227739-neo-n64-myth-cart-reviewPros:
+ Fits perfectly in N64 console
+ Multi CIC chip compatible+ Game instantly runs when booted up
+ Programmable Actel A3P125 FCPGA microchip logic core
+ 512Mbit of FlashRAM which is the same size as the largest commercial ROMs
+ Supports all games of the region corresponding to the console
+ Supports all different save methods for saved games
+ Supports homebrew ROMs
+ Games load instantly when N64 is powered on
+ USB 2.0 is relatively quick and easily reprogrammed
+ No CD-Rs or Zip disks to fidget with or slow parallel port cable
+ Supports multiple roms up to the capacity of the flashram
+ Clean, crisp display when playing games and no noise/interference
+ Removable flashram cartridge for more storage and replacement
+ Larger 1024Mbit Neo2 Flash Cartridge available
+ ROMs are stored indefinitely until flash RAM is erased or overwritten
+ Continued menu, firmware, GUI, and hardware development support
+ Neo2 SD for SD memory card support is currently work in progress to be added later
+ High quality printed circuit board and onboard components
+ Low solid state part count compared to old CDROM and Zip based copiers
+ Does not use external power supply or require batteries to store games
+ Does not require external power while flashing ROMs. Can be alone and not plugged into a console
Cons:
- No mass storage device support such as SD, TF, CF (SD support is still being worked on)
- No drag and drop support directly to flash memory (SD will have this)
- N64 console user interface is virtually non-existent
- No built in cheat code program (Action Replay is being worked on to be added to Neo2 Ultra Menu software)
- No real time save
- No built in region fix (Just use the appropriate region ROM or region fixed ROM)
- Takes a while to flash games
- Plastic black and not grey like original N64 cartridges
- Updating the core programming requires a separate USB adapter which is not included
- Supplied 512bit cartridge will only hold one 512Mbit game or two games only up to 512Mbit
- Takes a few minutes to program the Neo2 Myth Flash RAM Cart