A pity, that you cannot use them in html

IE 6 doesn't decode jb2

And you are able to look these pictures only in the program in which you encoded them

(PowerCompressor), a pity also that it (PwrCp) doesn't accept a lot of formats (gif, tif with LZW compression and so on)
So I have no choice but to use TIFF and CITT Group 4 compression

I just have a very big (hundreds of pictures) doc file, which I'm going to make a htm and to upload for ppl...
But before that to make it smaller I’ll convert with ACDSee all the pictures to the format which gives the best (smallest) file size.
Still, you are quite right, JBIG2 gives better compression than TIFF G4… A pity though that it so narrowly spread and it makes nearly impossible the usage of it…