I found a link to a bitcoin forum where a user was able to spend 10,000 bitcoin for some pizza in May 2010.
It's been said that this is the first time bitcoin was set at a specific exchange rate to fiat currency in order for it to be spent on something tangible.
https://bitcointalk.org/index.php?topic=137.0
The exchange rate at the time was $0.00250/1 BTC
At today's rate of about $654/1 BTC, that same pizza would cost $6,540,000 -
I think you can see now WHY people got into currency speculation!
Here's a webpage that has a list of USD to BTC exchange rates, tied to historically interesting events related to bitcoin:
https://bitcoinhelp.net/know/more/price-chart-history
Another article written about it a few years later:
http://motherboard.vice.com/blog/this-pizza-is-worth-750000