I couldn't resist linking across to this Symbian Developers post - I guess that, technically, the contents of the archives might be copyrighted to Nokia, but I doubt it'll mind at this stage for these operating systems and given that the resources are just images at the end of the day. What we have here are ZIP archives of the default 'out of the box' wallpapers for various Symbian generations, plus those for the Meego-powered N9 as a bonus.

From the blog post:

In this post we will upload all default wallpapers for Symbian^3/Anna, Nokia Belle/Refresh, Nokia Belle FP1/FP2 and Meego! If you’ve lost them in some way, for example when hard resetting your phone, you can download them here. You can also get some extra wallpapers from earlier or later S^3 releases and Nokia N9.

All wallpapers are stored in ZIP-files. Note that the wallpapers can take up much memory on your phone!

Download the default Symbian^3/Symbian Anna wallpapers: http://symbian-developers.net/wp-content/uploads/symbian3_wallpapers.zip

Download the default Nokia Belle/Nokia Belle Refresh wallpapers: http://symbian-developers.net/wp-content/uploads/nokia_belle_wallpapers.zip

I'll save the other ZIP archive links to make you visit the source page(!) Here's a glimpse into the graphical wealth contained therein, this time from the N9 archive:

Having sideloaded any wallpaper files you fancy, on a Symbian device you can change wallpapers by simply pressing and holding on any blank spot on a homescreen. After selecting an image from all the JPGs on your phone, there will be a couple of seconds delay while the graphic gets optimsed and resized to nHD etc. Be patient.