Some Graphics
Take a look at these two graphics about ePortfolios as Personal Learning Enviornments, or PLEs.
Graphic by Helen Barrett, a major researcher and practitioner in the ePortfolio field. (Helen is the "grandmother of ePortfolios):
https://sites.google.com/site/wheportfolios/home/resources-and-references/helen-barrett
Graphic by Scott Leslie, which combines ideas from a collection of graphics about PLEs.
http://www.edtechpost.ca/wordpress/2008/06/18/my-ple-diagram/