Flickr began as a photo showing site but not long ago they opened it up to artists as well. It is for just showing your work and a community, lots of groups involving just about every interest imaginable and can even start your own as I did (belong to many as well). Its run by yahoo so showing and posting there helps in people finding you through searches. Then most of us list our site(s) in our profile so that if someone really likes something they can find you easily or contact you through the site. Like here they have both a free or paid membership. Oh, and has a slideshow feature too, great for a link to give if asking to be reviewed by a gallery or agent.
Mine there if you want to look and check it out is - http://flickr.com/photos/11645220@N07/
and my group - http://flickr.com/groups/intricate-insanity/







