Below you are going to find some good sites where you could start building up your portfolio online to better present yourself and what you've done academically and/or professionally.

Visual CV
Also check some examples of what people have done with Visual CV

CarbonMade This is for more visual oriented portfolios.
Check some of the portfolios that people have created with CarbonMade

You also have the option to start up your own wiki site. Below are some good places to start up your protfolio wiki.

WetPaint

GoogleSites for free websites and wikis