Excuse me... if I did it at home - the school does NOT own my time except the 40 hours I am there. (If they do, then pay me for 168 hours / week :-P ) YES I do some of their work at home- BUT how do you distinguish what's on MY time at home and my donated time to them at home? IF I used some of their facilities or equipment (even the Library) - then yes- that's theirs; but if I don't, they don't own me and 100% of my time.

However most schools are generous and give you a % of the royalties. Plus they cover patent costs and maintenance of those legal documents which are expensive (they have to be maintained each year.) So it's worth it to let them handle it.
David (OFI)