Keeping it fresh

Salted Butter can be kept at room temperature for two to three days in warm weather, or for up to ten weeks in the refrigerator
Unsalted Butter can be kept in the refrigerator for six weeks
Butter can be kept in the freezer for up to 6 months, but might lose a bit of its flavour.

Soften it up

There are lots of quick ways to soften frozen or refrigerated butter:
Cut butter into small pieces, and set it on a plate over a bowl of hot water
Beat butter with an electric mixer
Roll butter with a rolling pin between two sheets of waxed paper
Heat it in the microwave - but keep your eye on it - it doesn't take long
Grate frozen blocks of butter to quickly soften
Melt butter carefully in a double boiler over medium heat

Part of a healthy diet

1 tbsp of butter has only 33 mg of cholesterol.
Butter contains healthy micronutrients:
Butter contains conjugated linoleic acid (CLA). Research indicates that CLA in the diet may reduce levels of body fat, and may also act as potential cancer inhibitor