Though Google almost always wins talent wars with the likes of Microsoft and Yahoo, its twin HR demons are startups and retirement.

Take the case of Niniane Wang, a 27-year-old engineer who received a million-dollar founders' award for her work on a program that searches computer desktops. She says she loves Google, puts all headhunter calls on "auto-reject," and isn't thinking about leaving ... but if she did leave, it would be to start her own company.

Then there are those who are coasting, waiting for their stock options to kick in, said to be "resting and vesting."

The solution? Google is considering starting a sabbatical program and thinking of new career opportunities within the company for the restless. It has also institutionalized, among other things, a bevy of compensation incentives, founders' awards than can run into millions of dollars, and special bonuses.

Full list: 100 Best Companies to Work For