I have recently been thinking about this as I am due for a promotion in a couple of weeks (I have been already been given the responsibility but not the consideration). In preparing myself for the conversation, I have been thinking of thinks to ask for that will make me more flexible rather than just getting more salary or bonuses. I am thinking about working a day a week from home or additional vacation days. Another thought was to get some education paid for... These are certain things that improve a lifestyle by not being attached from money but instead something worth more, time and knowledge...
I think there should be more of this kind of thing where the perks have personal value rather than just economic value. I think that it would actually help a lot with a range of society ills overall and those who can swing it, should consider taking other than money.