In some rather stunning work, Joseph AuBuchon, a graduate student in Sungho Jin's group at UCSD, has demonstrated how to make *bent* nanotubes. PhysOrg has a report here. (Check out the pictures!) They also claim to be able to make T and Y shapes out of nanotubes.
This could be a potential start towards methods that might be used to construct subcomponents for a real molecular assembler. That would allow one to bypass the chicken and egg problem we now face.