[sharpneli]

Pretty much all of the benefits of Bitcoin stem from the concept of blockchain, not from particular instance of it.

One has to keep this in mind when investing in Bitcoin. One doesn't invest in general future of cryptocurrencies, one simply invests in the blockchain that just happened to be first.

It is indeed a highly useful data structure. One can implement things such as verifiable online gambling (one where casino cannot cheat without being detected) with it. Basically it simply solves a byzantine generals problem.

The proof of work doesn't even need to be a hash. Primecoin searches for chains of prime numbers. As long as the work is easy to verify and hard to calculate with some sort of scaling it can be used. It would be nice to see things like Salesmancoin where the proof of work is partial solutions to traveling salesman problem. Or perhaps protein folding?