(keitai-l) Image formats on imode/ez/j

Hi,

If I were to make something that was VERY simple, not specific to any of the
phone companies, and had a few images in there, would it be best if they
were all small jpg files?  Can all the phones/companies handle them?

Also, if I was to make something that was in simple html, it SHOULD work on
all the different handsets, right?

Chris