Cost Evaluation for Stockholm Card - updated Summer 2010

Listed below is just a sampling of the admission to major attractions and transport included in the Card
24 hour card cost
Adult cost is           SEK 395    $53.46
Child Cost (7-17)   SEK 195    $26.39

Ferry to Djurgården                               SEK 40             SEK 25  (7-19)
Travelcard (public transport)                  SEK 100            SEK 60

Museum Admission prices                 Adults               Kids
Gröna Lund’s Amusement Park              SEK 90 (7-64) admission only, ride extra
Royal Armoury                                     SEK 70               free
Nationalmuseum                                   SEK 80               free
Nobel Museum                                      SEK 70               free
Skansen Open Air Museum                    SEK 120             SEK 50
Skansen’s Aquarium                             SEK 80
Royal Treasury/Palace                          SEK 130             SEK 65 (7-18)
City Hall                                               SEK 60
Vasa Museum                                       SEK 95               free

Historic Canal Tour                                SEK 140
HOHO Boat Tour                                    SEK 100

Sightseeing Tours
Boat sight seeing tours with Royal Canal Tour and Historical Canal Tour - free with card
Bus sightseeing tours with Stockholm Panoram & Open Top Tours - discount with card

My analysis:
If you are going to Djurgarden to see The Vasa Museum and Skansen (you will need to take the ferry), and see one other sight listed above the Card is worth it.

Other intangibles - usually lines for attractions are much shorter when you use cards like this versus have to join a queue to purchase tkts