I agree that registering at multiple sites is a great idea, to give guests a variety to pick from. Another great place to register that has about everything you could think of in one place is Amazon.com.
Of course you want nice things for your wedding! There are a number of nice places to register-BB&B, Crate and Barrel, Pottery Barn, Macy's,Bloomingdale's, etc. that are more than acceptable to register at, just be sure to include things at numerous prices points. And don't count out the high dollar gifts as unattainable, often times guests may combine their resources and get large gifts as a group!
Congratulations and Best of Luck!
Check out Bella's Party Planning section where I have a couple of new articles on weddings too!
http://www.bellaonline.com/site/PartyPlanning