Why not make this actually contribute to society rather than wasting energy to get some dumb number etc. !? It is not even finding new prime numbers etc. LOL
The POW should be actually something feasible and something of value.
That is a difficult problem to come up with a protocol that "does useful work" AND meets bitcoins other requirements:
a) that blocks be awarded equally and randomly
b) that blocks be generated at an predictable rate
c) that nobody can circumvent the network without 51% hashing power (network strength)
d) has no central authority
adding e) create useful "work" is simply not possible (yet).
If you can figure out a mechanism to tie useful work to block chain network WITHOUT A CENTRAL AUTHORITY I will support your "new & improved" bitcoin.
It is a very difficult problem.
Also I wouldn't say it is useless. I have an encrypted file system on my computer for privacy. Everytime I read or write a file it must be decrypted or encrypted. It isn't doing extra "useful work". Is my whole hard drive encryption "useless"? I would say no. The purpose is to protect my files just like the purpose of hashing is to protect the bitcoin network, and validate transactions.