- pointing to all eight directions
- round background
- in multiple colors
- nice looking (think "Web 2.0")
- permissive license
I searched Wikimedia Commons and a few other resources but didn't manage to find a good icon set matching all these criteria. Luckily these were more of a nice-to-have feature than an absolute requirement so I just went without the arrows then.
Later on at home I began to think it shouldn't be too difficult to create the arrows by myself. So, I surfed to Six Revisions, which is an excellent blog for web developers and designers, and did a few searches to their archives. Surely enough, I found a great tutorial for creating Web 2.0 -like icons.
The result you can see in sample image attached to this post. Download the icons (.zip file, 1.5 MB) and see them all. The images are saved as 256x256 pixel PNGs with transparent backgrounds. There are 48 different images: all eight directions in white on green, white on yellow, white on red and inversed colors. I have licensed them with the CC0 1.0 Universal license which is effectively the same as giving them into public domain. In other words you are free to do whatever you want with these images, no restrictions. I would appreciate a note if you use them somewhere but that's not required either. Enjoy!