biteasy, thank you for your reply.
But I don't think you would be happy if I requested something like all the addresses in existence.
It seems like the only way to solve the problem is to parse all the blocks to a database using getblock/getrawtransaction/decoderawtransaction commands to a bitcoind server.
heh, yeah you are right, it wouldn't be possible to do that.
Parsing the blockchain yourself is the only way to go for what you need.
Maybe this will be helpful to you:
https://code.google.com/p/blockchain/