I’ve always disliked full-desktop wallpapers. I really hate images that cover my entire desktop since it makes it hard to distinguish icons. Or the icons cover parts of the desktop thus ruining the image/photo.
Since I usually work in 1152x854 or 1280x1024 resolutions, I’ve always downloaded 800x600 versions of desktops I liked. But that is over now. I found few sites with beautiful photos in 300-500px sizes.
First is Ten years of my life. It is updated daily as off-project of Matthew Haughey, of the A Whole Lotta Nothing fame. Some of the photos are simple, some have unusual composition, there are lot of focus-plays and some simply feature beautiful subject.
Second is 28mm. Updated monthly, this site features works of professional photographers as well as hobby photo-shooters. There are several thematic series per issue. Be ready to be surprised and amazed.
Both sites have RSS feeds, so you can track them that way.