I also emailed this to you with a copy of this picture I mentioned below.
http://www.angelfire.com/biz/rcwebcr...activity4.htmlhttp://www.nickjr.com/grownups/parti...nvite_blue.gifhttp://www.party411.com/forums/birth...ages/2175.htmlhttp://www.geocities.com/dad4xfun_20...luesclues.html
A lot of these, I had copied and printed out. I made the cutest hats. Look under the family photos, silly mugs, lets see your cry babies, to see one.
As far as invitations go, I made paw prints, three for each guest. One the back of the first, I put a copied picture of Blue's House. On the second one I put a birthday cake and Happy Birthday. On the third, I put a copied picture of Duncan. I gave them out once a week. (you could mail them like that, or mail them all at once.) I have a few more ideas, so if you have specific questions, feel free to ask.