Welcome to the forum.
Although those cameras may look similar, the Canon is a vastly superior camera. This is because the Rebel XT is a true DSLR (digital SLR) while the Fuji is "SLR-like".
The biggest difference is the size of the sensor. The Fuji has a very small sensor, while the XT's sensor is much larger. This means better image quality...especially in low light/high ISO.
Also, the XT can shed it's lens...allowing you to use any of Canon's EF lenses...or any other lens made for Canon autofocus SLR cameras. With the Fuji, you are stuck with what you have. Additional lenses are expensive, however, lenses will hold their value much better than any digital camera...because you can use the lenses on future cameras...if & when you decide to upgrade the camera.
Shutter response: Most non-DSLR digi-cams have a shutter lag. When you press the button, it waits for half a second or so....before it snaps the pic. The XT has an actual shutter like a film SLR...so the response is very fast.
On the down side, a DSLR won't allow you to view the image on the screen before you take the picture...and it does not have a movie mode.
You can check the specs and compare them head-to-head at
www.dpreview.com