Although your work will be similiar in each portfolio you create, you may be reaching a new audience on each site. You may be meeting new people, exposing them to your work, and making new connections by placing your portfolio within totally different communities.
There are plenty of social networks - try joining sites tailored to your talents. Undergroundfilm and Videoart are social networks specifically designed for filmmakers and video artists. Under is a list of five social networks which have creative individuals in mind.
Deviantart
http://www.deviantart.com/
Founded in August 2000, deviantART is the largest online social network for artists and art enthusiasts with over 13 million registered members.
Featured Profile: Arenyth - Digital Painter Based in Belmot, CA
Behance
http://www.behance.net/
The Behance Network is a platform for creative professionals across all industries.
Featured Profile: ISE Ratinan Thaijareorn, Illustrator based on Bangkok, Thailand
Spraygraphic
http://www.spraygraphic.com/
Spraygraphic is a virtual comunity for creative minds. Founded in Feb 2005 by Chuck Banaszewski and Matt Krise.
Featured Profile: Simonas Sileika, Photographer based in Vilnius, Lithuania
Videoart.net
http://www.videoart.net/
Videoart.net was founded by video artists and filmmakers based in New York City, and is dedicated to video art and short films but interested in any artist utilizing the video medium.
Featured Profile: Lar Peterson Hernandez
IndieGoGo
http://www.indiegogo.com/
IndieGoGo is a collaborative way to fund ideas. Founded in 2008 with the objective of providing any idea (creative, cause or entrepreneurial) the tools and process to raise money, offer perks and keep 100% ownership.
Featured Profile: John Trigonis, indie filmmaker & poet based in Jersey City, NJ