I'm surprised that someone hasn't started another Bitcoin yet. Is it harder than just changing some initial seed? Because the artificial scarcity of digital currency is what's allowing for these high prices.

Then all you need is intermediary parties that will exchange your V2 Bitcoins for V1 Bitcoins (which will currently have the highest acceptance for buying things). Over time, V2, V3 etc. may even become accepted directly by merchants, if they become big enough.

UPDATE: Thanks for the info on additional ones. This is getting really interesting. So my initial scarcity hypothesis was wrong, which means it's just pure herd mentality. Hopefully over time the availability of multiple currencies will lead to some sort of equilibrium though.