Ask HN: Employee services providers and stock options

Maybe somebody here can help me understand something: There are companies out there (such as Paychex [http://smallbusiness.paychex.com/]) that provide "employer as a service". In other words, a company contracts with them to be the employer of record for an employee, then the company hires that employee as a contractor from the provider. The benefit to this is around things like group health care benefits. Instead of a group plan with four people, you are part of a group plan with thousands. It also removes the day-to-day accounting crap associated with employees. The question I have: Does anybody know how those types of arrangements work with stock options in the actual small business? Has anybody had any experience with that kind of an arrangement (either as the employee or the employer)?