All xD memory cards are made to the same standard.
All xD memory cards are interchangeable.
Olympus Optical Co., Ltd. and Fuji Photo Film Co., Ltd. (Fujifilm) of Japan jointly developed the xD-Picture Card.
...
..
.
I am thinking of buying the Fujifilm E550 but want to upgrade the mem. card. Officemax has an OLYMPUS XD 256mb card for $30. Can I use this in my Fuji camera?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic