Thanks for the input guys. From what I've heard so far it seems that 90x120 and 88x88 are the way to go.
Interesting idea about the golden proportions but I'm not sure if its practical. From the examples Brujah posted, they look far too long. The standard photo size about 1:1.5, so less. I dont' think the golden proportions would actually look good, plus the problem with it being uncommon as discussed above. Thanks for the idea though.
