This is something that's been in development for years and has now been released to the public: The Satiator Optical Disc Emulator by Prof. Abrasive
It's essentially a flash cart that plugs into the VCD slot in the back of the Saturn and lets you load games right off of that. There are a couple other ODEs out there for the Saturn, but I really like the fact that this one doesn't require removing the actual disc drive (I don't plan to part with my discs anytime soon) and can easily be removed and put into another Saturn if need be. I also love that it leaves the cartridge slot free, so I can finally play the Tamagotchi game that requires a memory cartridge to save onto. It's expensive, but considering the price of Saturn games these days, I think it's a worth the cost.
I've ordered one and am really looking forward to trying it out! Game compatibility isn't 100% yet but it seems that folks are expecting everything but games that require the VCD-card will be patched into functionality soon.