Some websites that might be useful:

WeddingChannel.com - Display your registry, provide wedding logistics, find vendors and create a wedding website.   Here's our page.

Ultimate Wedding Online - The online wedding mall offers a large catalog of wedding items, sometimes with free shipping.   

The Knot - Can be used as a supplement for tracking wedding plans.  Post registries and a web page as well.  

Modern Bride - Useful for comparison shopping for bridal and bridesmaid gowns.  It also has an interactive wedding planner. 

Surprise.com - Offers gift ideas categorized by the recipient rather than the type of gift.  Find gifts for the wedding party, family and friends, and your spouse-to-be.

About.com Wedding Forum - Still have questions or need opinions?  Ask the experts by joining a wedding forum.   

Target Club Wedd - We registered at Target, in addition to Macy's, and we received a free one-year membership for Target Travel Club. 

Disney Fairy Tale Weddings - Interested in Disneyland for your wedding or honeymoon?  The basic reception is a very good deal, but when you get into Disney themes, that's another story!  The wedding managers are very good, though, so we do recommend them.

Christian Wedding Planning Center - We've heard some negative things from former clients online. We did not have any major problems, but we did have to double-check their work often.  We also did not employ much of their services for our reception, which seemed to be a main source of complaints.