How do I export my private keys from my Bitcoin-Qt client? Trying to use this posted method:

To export a private key from your Satoshi bitcoin-qt client:

launch your bitcoin client as usual and wait for it to load the blockchain and start up
click on 'help' in the menu bar (top right)
click on 'debug window'
select the 'console' tab
type: walletpassphrase "your walletpassphrase here" 600
type: dumpprivkey [your bitcoin address here]
this will return the private key, you can copy it now; ensure you clear your clipboard/history afterwards
type: walletlock


I do not understand what "your walletpassphrase here" means.  I do not have a wallet pass phrase to the best of my knowledge.

Also, I am a bit of an amateur at this and I still don't understand the "your public key here"..... is that the address that corresponds to your wallet? [Update: Yes, the bitcoin address.] 

Trying to export the private key to another wallet because the bitcoin wallet has taken 2 days to sync and is still not done.

Any help would be very appreciated.
I believe that listreceivedbyaddress 0 true does not list the change addresses that are created as part of the normal client operation.

Starting from bitcoin 0.7, you should use bitcoind listaddressgroupings to get all the addresses, and then follow up as usual with dumpprivkey.