I absolutely LOVE the designs on this website: http://www.invitingsmiles.com/Birth-Announcements-Home-Page.htm
http://www.tinyprints.com/birth_announcements.htm
http://www.babiesonline.com/printannouncements/birthannouncements.asp
I love these, and hope to use them someday myself...
http://www.youreinvited.net/birthannouncements/birthannouncementone.html
I really liked the idea for these tape measure ones on Matha Stewart: