wallbase.cc is an excellent site to download wallpapers with an option to search through the wallpapers database which are tagged.
But with literally a huge database it takes ages to download the wallpapers to browse and download.
So if you are in a hurry just use the wallbase script to leech the wallpapers of the site and then sort them at your leisure.

This Script is written for GNU Linux, it should work under Mac OS

Changelog :

• Revision 2.8
  Contributed by MacEarl
  1. Added Option to rename files accordingly to their tags. (experimental)
• Revision 2.7.1
  Contributed by MacEarl
  1. Fixed Login, everything should work again (except the related wallpaper feature)
• Revision 2.7
  Contributed by MacEarl
  1. Fixed most issues (wallbase v4 update). No need for Base64 anymore
  2. Login Feature does not work, that means no nsfw wallpapers,
     Favourites or Uploads from a User (Collections with some nsfw Images
     will be downloaded without the nsfw images)
  3. Download related Wallpapers Function does not work
     (it seems the related Wallpaper function was removed, if you find it please let me know)
• Revision 2.6.2
  Contributed by MacEarl
  1. Fixed Download related Wallpapers Fuction (just forgot to add the base64 stuff last time)
  2. It is now possible to download a Range of Wallpapers with all related Wallpapers
• Revision 2.6.1
  Contributed by MacEarl
  1. Fixed Download Function (They added base64 encrypted urls).
     The Script now uses "base64" to decode those urls so make sure you got that installed ;)
• Revision 2.6
  Contributed by MacEarl
  1. Added Function to download Related Wallpapers
• Revision 2.5.1
  Contributed by MacEarl
  1. Added some Explanation in Section 6 to clarify the combination of the THPP and Max_Range Variables
• Revision 2.5
  Contributed by MacEarl
  1. Added a Feature to download a specified Range of Wallpaper
• Revision 2.4
  Contributed by MacEarl and HansTester
  1. Fixed Login Feature (NSFW working again) (Thanks to HansTester)
  2. Implemented download uploads by specific User (Thanks to HansTester)
• Revision 2.3
  Contributed by MacEarl
  1. Added Categorize Feature
  2. Source Cleanup
• Revision 2.2
  Contributed by Axa-Ru and MacEarl
  1. Source Cleanup by Axa-Ru
  2. Fixed Download Code for new System
  3. Improved the check for already downloaded Files ( much faster ;) )
• Revision 2.1
  Contributed by MacEarl
  1. Added a Feature to download "Your Favorites"
  2. Added a Feature to download "user created collections"
  3. Rewrote the check for already downloaded Files
     (You now can rename or remove Wallpapers and they dont get downloaded again.
     Eg. If you don't like a wallpaper, just delete it and it won''t get downloaded again.
     To re-enable the download of a specific Wallpaper you need to remove the Wallpaper number from the file "downloaded.txt")
• Revision 2.0
  Contributed by MacEarl
  1. Rewritten code for new Wallbase System
• Revision 1.2.1
  Contributed by MacEarl
  1. Added Login Check for new Wallpapers
• Revision 1.2
  Contributed by MacEarl
  1. Added a login feature to download NSFW content/category
• Revision 1.1.1
  Contributed by Hab
  1. Updated mkdir option with -p flag
• Revision 1.1
  Contributed by MacEarl
  1. Added a Search Function
  2. Added a check for already existing Files
  3. Fixed a bug (imageshack mirrored files)
• Revision 1.0
  Contributed by MacEarl
  1. Added the much needed fixes for NSFW category
  2. Updated the script with more options
  3. Modified the script