They're probably used to 6 weeks a year of paid vacations. Many people who like to travel or spend long weeks at the beach with their family would be happy to get more vacation in exchange for lower base salary, and they'll be more productive to boot. It's worth about 50 cents. There are a whole bunch of things you can give employees which cost less than they seem to be worth. Almost every software company has free soft drinks.
Massages seem to be popular in Silicon Valley.
I've heard of a consulting company that is setting up beach houses and ski houses for employees to use. Microsoft has subsidized espresso carts in practically every building. Google has a gourmet chef with free lunches and dinners. Health club memberships cost a lot less than you think if you buy them for all your employees, because only a fraction of them actually take advantage of them. Every Microsoft manager has a morale budget to use as they see fit.