Here are a few FREE online portfolio sites you can upload your art to:
Coroflot.com - Online Portfolio, FREE, 5 images, brief summary of your skills and experience, plus your full resume
http://www.coroflot.com/
ArtAndDesignOnline.com- Online Portfolio, FREE, 4 images (& 3 Sample Images), About Us, Statement & Find Us
Voodoo Chilli - Your first 5 images are free, but after that you have to start paying.
http://www.voodoochilli.net/
Alpha Omega Digital - Online portfolios include samples of your work, professional information, resume, contact information, logo, personalized URL, guest book and more.
http://www.alphaomegadigital.com/
At Creative Hotlist, you can browse posted freelance jobs for free. A portfolio page at this site is $35 for 6 months, but it's free to create an individual listing which includes a link to your portfolio page elsewhere.
http://www.creativehotlist.com