Do only Olympus cameras use xD memory?

Yes Olympus cameras only ever use xD memory cards to date. Fujifilm is another brand that has used xD for a long time, but now they are making all of their cameras both xD and SD compatible. I expect that Olympus will eventually do the same. My credentials to answer this question come from the fact that I have been a professional photographer for the past four years and now I also work in the camera department in Best Buy.