Hey All (Not that I don't think there is (m)any!
I have recently joined a social network devoted to promoting designers! It's called Behance.net
It is really worth checking out, You can set up portfolios and join 'circles' (groups), etc.
If anyone would like an invite please leave a comment, I have also created a group for young designers who want to make an entrance :D
http://www.behance.net/Circles/Young-Designers/48215
Cheers,
Matt.
P.S Here is a flickr group I just made too :)
http://flickr.com/groups/youngandupcomingdesigners/