I always name them .wallpaper-name.desktop so they're hidden files when browsing (like the default ones). An example for this background set: Code: N900:~$ ls -al MyDocs/.images/ | grep schmoke360 -rw-r--r-- 1 user root 297169 2010-08-07 08:23 schmoke360a.png -rw-r--r-- 1 user root 346974 2010-08-07 08:23 schmoke360b.png -rw-r--r-- 1 user root 255602 2010-08-07 08:24 schmoke360c.png -rw-r--r-- 1 user root 284 2010-08-07 08:27 .schmoke360.desktop -rw-r--r-- 1 user root 314342 2010-08-07 08:24 schmoke360d.png N900:~$
N900:~$ ls -al MyDocs/.images/ | grep schmoke360 -rw-r--r-- 1 user root 297169 2010-08-07 08:23 schmoke360a.png -rw-r--r-- 1 user root 346974 2010-08-07 08:23 schmoke360b.png -rw-r--r-- 1 user root 255602 2010-08-07 08:24 schmoke360c.png -rw-r--r-- 1 user root 284 2010-08-07 08:27 .schmoke360.desktop -rw-r--r-- 1 user root 314342 2010-08-07 08:24 schmoke360d.png N900:~$