In a slightly ridiculous turn of events, it appears that Logitech may be producing an external UMD drive for the PSP Go which would enable gamers to play their UMD titles on the portable console, according to a source quoted by CVG.
It'd likely plug into the PSP Go's memory stick port on the left of the device in a similar way to how various hard disk add-ons released for older PSP models did. There's no price or release date info yet.
Of course, a large part of the rationale of the release of the PSP Go in the first place was the removal of the UMD drive from the PSP and the use of flash memory instead. Adding it back in would make it into what would essentially just be a very expensive PSP-3000, albeit without a replaceable battery and with a smaller screen.
We've been trying to get a confirmation or denial of the existence of the product from Logitech, but have neither so far. We'll update this post when we hear back.
Update: Logitech has denied plans to produce this peripheral.