@Monika - I see what you're saying, but I still think this technology should be developed. I don't think we should avoid developing new technology just because of how it could possibly be used. If we did that, we would never develop anything new.
Anyway, I think it would be pretty awesome if we could use nanorobots to build small things. Imagine how small computers could be if we had nanorobots to build all the tiny parts.