I know after having the same wallpaper on my computer for a while I start getting bored with it, but its so hard to actually find high quality images that you like. Here is useful tool to simplify downloading of wallpapers task as well as make it easier for you to manage wallpapers, MSN wallpaper manager from widows live team. Windows Manager lets you change your desktop wallpaper at regular interval or based on time like on lunch, working hours, weekend etc.
MSN Wallpaper Manager automatically downloaded wallpaper library in background to provide refreshing wallpapers every day. You can also personalize by adding text, speech bubbles, graphics element 7 foreground images. You can download MSN Wallpaper Manager here.

Today I came across a great desktop screensaver that I have been trying to find for ages. Since I do a lot of business in a variety of time zones it is great to know what time it is anywhere in the world at a simple glance, and EarthDesk provides this.
EarthDesk is much like Wallsaver but the wallpaper is set to an image of the earth which shows which countries are in daytime, nighttime and all in real-time. The program is currently free for both Mac OS X 10.4+ and Windows 2000, XP and Vista. The amazing interface also tracks information on 10,000 cities throughout the world and can display cloud cover and even cyclones

EarthDesk also gives you numerous options for configuring map images on your desktop. Maps can be centered on a city, so that the map remains stationary while the sun and moon move. Alternatively, the map center may be locked to the position of the sun or moon so that the shadow remains fixed, while the map moves.
EarthDesk is definitely one program to grab while it is free. Click here for the free download.