this was my second ps3-theme.
i did it by tracing the sample icons in Artrage (a program packaged with my wacom
and adding a little doodling giving them a feeling of something beeing scribbled down in the margins of a notebook. (i have a nasty habit of doing this. often ends up with more doodles than notes
to install the file on your ps3 you get yourself an usb-drive (or some other memory device useable by ps3) and create the folders PS3/THEME and add the file into the THEME folder.
then pop the memory device into your ps3 and go to theme settings and select install from the top and your device should show up. (i think that you need atleast fw2.00 for themes to work)