Storkie, an online stationery site offering announcements, invitations, labels, and my favorite...custom wedding stamps. If I could do my wedding over (a sentiment many of us feel now that we are older, wiser and have better taste! ha!), I'd love to create a custom stamp for my invitations. I remember agonizing over the stamp selection when I got married 12 years ago and think that a detail like this would've been such a fun addition.
You can check out the custom stamps here and their other offerings here.