I am generating lots of other interesting addresses and I want to sell them.
This can't work. You will still have the private key of those addresses, which means you can spend any coins sent to them. You cannot
sell an address, you can only
share it, which hardly anybody would be interested in.
Firstbits.com could allow pointing of the address to another, no?
A) I find 1NickABCD, and "1Nick" is the firstbits after I send 0.00001 btc to it.
B) Along comes Nick Smith who wants to buy 1Nick for 10BTC.
C) Nick Smith Generates 1NickXYZ... on his own and sends 0.0001 btc to it
D) I send the private keys of 1NickABCD to Firstbits and the pointer 1NickXYZ...
E) Transaction is complete, I get 10BTC
Private keys of 1NickABCD are then published on firstbits. Now 1NickXYZ... would show up at firstbits as "1Nick"