Paperless Post now has many kinds of cards you can customize: thank you notes, save the dates, announcements, birthday cards. And you can make professional stationary for your business as well.
The service is chic, cheap and obviously eco-friendly. And just like Pingg(which I prefer over Evite), it has a great tracking system for RSVPs and comments.
My note to MTM readers here says:
Dear MTM Readers,
Thanks so much for your patience while I renovate the site.
As always, if you have any questions, never hesitate to email or tweet me.
Hope you are enjoying the beautiful spring weather.