Allowing employees to donate 10% of their work time to nonprofits of their choice. Employees feel like their company gives a crap and helps them feel like they're a part of something bigger than themselves.
This is good, but these kinds of deals are almost always more of a gimmick than anything else. If I work 36 hours and volunteer 4 hours, chances are I'll probably still be given 40 hours of work rather than 36.
Yeah, I suppose it depends on the type of business. If the business espouses the 37Signals philosophy of not overworking employees, then it can be a good thing. If not, then it could just lead to more work.