I'm really happy that 1 BTC = ~$5.1 USD. The reason I wanted to know how to make it worth more was to know what would the impact be if I built a 40gh/s mining equipment. Like, if the reason why it went from $20 to $5 was because ppl started mining more, then I would prob not spend that much on my rig.
Last year's "crash" was because the bubble burst. Back then, Bitcoin's value was much lower than it is now, but speculators kept on buying like crazy. An exchange got hacked, which caused a sudden mass realisation in many people's minds: "I paid too much". And when a lot of people suddenly don't want a product any more, what happens to its price? However, thanks to Bitoin's mini DotCom, and continued investment by entrepreneurs, the market is now more mature and the economy has a lot more value supporting that ~$5 exchange rate.
With 40Gh/s you would control around 40/12000 = 0.33% of the total mining supply. And then there's circulation of older coins. So the price probably wouldn't change much no matter what you did with the coins. You could stick them for sale on MtGox or Intersango for $5.30 each, or how about $6? The other miners would have slightly less bitcoins to sell, so they might be inclined to put their prices up slightly. Whether or not people actually buy at a higher price is another matter.