The E-R0001 "PlayStation 3 Harmony Adapter" turned up on the FCC's website, but has yet to be formally announced by Logitech. As such, there's no word on which Harmony remotes it will work with. We've contacted Logitech in hopes of finding that out -- along with other details -- and will update you when we hear back.
[Update: Logitech has updated its blog with more details on the device from global gaming product marketing manager, Troy Petersen. You can read his comment after the break.]
"Yesterday, an Engadget reporter did some digging on an FCC Web site and uncovered our plans to manufacture an adapter that allows our Harmony remotes to control the PS3. We can't give you all the details just yet, but we can say that this adapter will, when used with any Harmony remote, give you complete control of your movie-watching experience on PS3. It will also turn the PS3 on and off – and allow you to set up your Harmony activities to include the PS3 just as you would any other device. You also won't need to dedicate any of your valuable USB ports to get that control."