I have done it for trial only (no special confiruations needed), what you need to think about for is real use, because Oracle needs a lot of memory. Probably you would like to have more than one disk, and in on of them will run just Oracle.
I have been using Openacs and acs in the same box, openacs for real life use and acs for demos to clients and no errors, just be careful with your swap partition (like aD folks says, at least 400Mb or 2X yout total amount of ram).
