Yes, I have done this. I actually moved the entire installation, not just the .dbf files, so I don't know exactly what your steps would be to get Oracle to see the data, but I'm sure it can be done. Probably just making sure that you replace *all* the .dbf files, so you get the data dictionary, not just the ones you created for your data.
I should note that I don't really recommend moving the entire installation because it's a PITA. You have to go through and edit a bunch of files which reference the system name and/or the SID (which I tie to the system name). I did it because it took *forever* to run the instsallation GUI over our old 56K frame relay. Now that we have a T1 I don't worry about such things anymore. :)
