What is the early history of the BTC exchange rate? Trading on Mt. Gox, which is now the largest Bitcoin exchange, started in July 2010 at an exchange rate of $0.05 USD. This comment suggests that on May 2010, bitcoins were traded at bitcoinmarket.com for roughly $0.004 USD.

What other exchanges existed this early in Bitcoin's life? What is the earliest/lowest recorded exchange rate?
According to https://en.bitcoin.it/wiki/History:


  2009
  October 5 Exchange rates published by New Liberty Standard. $1 = 1,309.03 BTC (and theymos thought NLS was overcharging[3])


It cites http://newlibertystandard.wetpaint.com/page/2009+Exchange+Rate
and
https://en.bitcoin.it/wiki/History#cite_note-2

That first citation seems to have a decent list of pre-May 2010 exchange rates.