Some great Creative Commons licensed artworks by Canadian 3D artist Jesse Lang (aka Dark Geometry Art), who creates "fantasy and science fiction" artworks.

Feel free to use them in your post or in an art-project. Just keep in mind, that all of them are licensed under NC, which means, that they must not be used commercially.

Infected Cyborg by DarkGeometryArt under CC-BY-NC-SA 3.0 license.

aNONYMOUS by DarkGeometryArt under CC-BY-NC 3.0 license.

Green eyes by DarkGeometryArt under CC-BY-NC-SA 3.0 license.

Here are some more places to find artworks of Jesse Lang:

Homepage
Deviant Art
Twitter