The Genographic Project
Diffusion is the most interesting part of Geography. I will be eagerly awaiting the results of this study:

Gene Project Aims to Trace Human Migration.

Here's the project's official site:

You and I can even take part:

The project is also inviting participation from the general public, for a fee. People may buy a kit for $99.95 (plus shipping and handling) that will allow them to scrape the matter from the inside of their cheeks and send it in. They will receive information about their own migratory history, and their data will be included in the master database. Participants will receive updates on the project and other materials as well.

Here's how: How to Participate - The Genographic Project.