Skeincoin uses Skein and SHA2
Blakecoin uses Blake and SHA2
Quark uses 8 random algorithms and as clones of it so do SecureCoin and Offerings
Can a GPU mine Skein and Blake?
I believe there is a Blake GPU miner in the thread for Blakecoin. Skein's GPU miner isn't finished, but there's active development going on in the SKC thread.