Exo biology or astrobiology is a relatively new branch of science that is concerned with the origin, distribution, and evolution of life.
Exo biology deals with questions like: What is life? Is there life in other planets?
Here is a selection of some recommended Exo-biology sites.
Exo Biology @ Nasa - Exobiology section of the NASA website. Contains a brief introduction to exobiology as well as links to various research groups.
Exobiology @ duke.edu - Includes sections on the prebiotic earth, the Miller/Urey experiment, possible sites for the origin of life, the search for life outside of earth, politics and controversial issues, and careers in exobiology
Please feel free to share your favorite Exo-biology websites (with a short description).