If you are able to get enough people to do this it would work by definition.
But my guess is that there are too much people involved for this cartell-like market manipulation.
This would just create another bubble which would crash.
The right thing is as suggested, use them for services as much as possible. Every time a merchant blows their horn about doing so much $$$ revenue in BTC it raises the profile and might entice other merchants to accept it and thus increase demand.
For me a big win would be if Wikipedia accepted donations in bitcoin.
I have sent an email .. now if everyone in this forum did that, I think the price would increase.
We are trying to make it easy for people in every country to donate. Please let us know how we could make it easier for you. Send your suggestions to: problemsdonating@wikimedia.org.