What about peercoins? Can those be mined using GPU or is ASIC a must?
PPC is SHA256 based. In other words, an ASIC is necesarry. With a GPU you can only reasonably mine SCRYPT based currencies, e.g. LTC, FTC, DGC etc.
Is PPcoin mining prevalent? With the cost of ASIC miners. Mining PPCoin should be prohibitively expensive to many.