The two cameras are very much alike and you won't go wrong with either.
Here is a comparison of the two:
Notice the green link right under the photo of the camera.
That takes you to a full review of each camera.
I'm looking to purchase a new digital camera and am comparing the Canon PowerShot Pro Series S5 IS 8.0MP Digital Camera with 12x Optical Image Stabilized Zoom vs. the Sony Cybershot DSC-H7 8.1MP Digital Camera with 15x Optical Image Stabilization Zoom. I would greatly appreciate any feedback that you may have.