One site I highly recommend is Squidoo.  It is one of the best ways to get onto the big search engines if you have an online store, or website.

I currently have 3 lenses and one group set up in Squidoo.  Feel free to check them out, vote and comment.  My 3 lenses are below-

http://www.squidoo.com/caring

http://www.squidoo.com/designstores

http://www.squidoo.com/travolta

This links is my group that relates to print on demand stores.  If you are a designer of a print and demand site, please feel free to join this group listed below -

http://www.squidoo.com/groups/pod

Other groups that are great to join are also for designers.  These groups are quite a learning experience and we have great discusssions plus a lot of fun.  If you currently design or plan on starting custom designing online, join these 2 groups for sure!

http://groups.google.com/group/zazzlecom-contributors

http://groups.google.com/group/print-on-demand-united

A really cool social network I recommend is Yuwie.com.  All ranges of ages belong.

http://ww3.yuwie.com/yuwie.asp?r=78140&vid