i brought a ton of photos today for you guys, but they are all 600x800 and the site will only accept 600x600.
I have no problem posting 800 x 600 and even larger on this site. You do have to get them under 300 kb so you need to compress them quite a bit.
eg Here is a 1024 x 683 size photo that is only 60 kb.
BTW That's the instructing luthier (Chris Wynne) playing my guitar - during classes every few hours he'd pick up a guitar an give us a number or two - kinda like a two week long concert!