What do you do if your partner likes a firm bed and you like a soft bed?

Tell us what you have done in order to come up with a mattress to fits two opposing sleepers.  It is not as difficult to come up with a compromise when one person is hot and the other is cold but when one person wants a firm bed and the other wants a soft bed you have problems.  So we want to hear from you, our readers, what is a good solution to this age old dilemma.