Awesome-Wallpaper downloads the best pictures every day for your desktop wallpaper to keep it interesting. It is a script made to work with a cron job (scheduled execution) to download new photos every day.
1: Ensure Python is installed. It probably already is, but to check, go into terminal and type "python" and see if it responds.
2: (Mac OS only) Open terminal and enter*: rm ~/Library/Preferences/com.apple.Desktop.plist
3: Make a directory for your wallpapers, it can be anywhere.
4: In your computer's operating system settings, make your wallpaper directory point to the directory you just made and make sure it allows multiple wallpapers as well as timed switching.
5: Download ~get_todays_wallpapers.py and put the file in the same wallpapers directory you just made.
6: Create a cron job to run ~get_todays_wallpapers.py at the interval you choose**
*All this does is make it so that Mac OS doesn't switch your wallpaper back to the default when you restart your computer.
**How to create CRON jobs:
Here is a good tutorial for creating cron jobs on a *nix system with Crontab.
If that scares you, I recommend using Google's free software CronniX to schedule cron jobs (only Mac OSX).