The South Australian Museum took you on a tour of their physical museum using staff to show both their collection as well as the physical space. The overall concept of using real people and collections is simple, yet effective.
Museum Victoria's greeting is very classy and I liked that you could also view in audio description.
The Cooper Hewitt's 2010 greeting designed by an award-winner is great, and is in keeping with their ethos of good design.
The work being done at the Denver Museum of Nature and Science is stunning. Their holiday greeting, Apatosaurus lands triple axel in City Park!, is really cute. However, it was their Gengis Khan promotional video that really grabbed our attention - what a simple, yet effective piece of marketing!
Finally, the Powerhouse Museum's blog post How many museum professionals does it take to make a Christmas card…? shows not only the card itself but provides an insight into why and how they produced it - gotta love that.
Feel free to add any e-cards that have taken your fancy.