Why don't you take a look at:
There's a 'splash screen' link on the left.
If you go there and select any of them, you get a 'download' link and a 'how to install' link..
Here's what it says:
'How to install a splash screen
# Open konqueror
# Create the directory ~/.kde/share/apps/ksplash/pics
# Browse to ~/.kde/share/apps/ksplash/pics
# Move and uncompress your new splash screen file into the konqueror window
# Have fun! :-) '