Several problems with large byte arrays

Tubeglow wrote:

Apparently, creating an array that's longer than the
size of RAM can compile without an error

Can and usually will. The compiler is very trusting about such issues. PROGMEM does work reliably (on my duemilanove at least. I embedded a couple of images for a recent projects using it; the largest one was about 5.5KB and could be read (in lots of small chunks ;)) without trouble.