Basically you need to maintain some legal status between F1/OPT and H1, otehrwise what do you call yourself?
If possible, file I140 AND I485 and then you will be AOS status. Hopefully that will not be denied before 10/1/2008 (when your H1 can start).
If possible, file I140 AND I485 and then you will be AOS status. Hopefully that will not be denied before 10/1/2008 (when your H1 can start).