7Print, Inc.

Design free greeting cards with an online design utility and print them for immediate use or place an order for professionally designed greeting cards.
http://www.7print.com/

Printfree.com

Free cards to print or download, for holidays and other occasions.
http://www.printfree.com/index.htm

Ecardiy

Make and send musical greeting cards easily and quickly using a guided operations graphical interface. Users can change font, color or style of greeting messages, support true color. FAQs, support, download free trial. [Windows]
http://www.ecardiy.com/

About.com Desktop Publishing: Cards & Invitations

How-to articles, tips, links to software for creating cards and invitations.
http://desktoppub.about.com/cs/cardsenvelopes/

Printable Greeting Cards

Design printable greeting cards, photo prints directly from the web. Membership is required to access software, fonts and galleries of printable designs.
http://www.picturebuzz.com/

Birthday Bash

Create birthday invitations and greeting cards with user art.
http://www.winslowpress.com/newsite/rrita/RR_root1/rr_book1/birthdaybash/birthdaybash.cfm

Fun Vouchers

Print occasion gift promise certificates.
http://www.fun-vouchers.org.uk