I just received my Lensbaby (for use on a Nikon D70), and had to go out immediately to get a wide adapter. I couldn't find the Sony 0.6x unit, but I think it is not wide enough anyway for the Lensbaby on a DSLR. But I did find a 0.45x semi fish-eye conversion lens made by Vitacon with the correct 37mm outside thread. It is the Titanium 1045N.
The lens comes in two parts. If you unscrew the front lens element you get macro capability.
The cost was SGD140 (including 4% GST), or about USD80.
Cokin makes a slightly wider 0.43 adapter, also with macro capability. I didn't ask for the price.
/Ben