I only run 4 desktops, but I've got to the point to where I could not do
without multiple desktops.
1. Firefox
2. Thunderbird
3. Gimp
4. OpenOffice or AbiWord.
1 & 2 are always running Firefox and Thunderbird. 3 & 4 are usually
left open, but when used are used for photo editing and/or word processing.