Can I freeze fresh berries?

Yes. Strawberries can be frozen for up to a year. However, after defrosting, they will look darker and exhibit a softer texture. For best results, wash and hull the strawberries, then sprinkle them with sugar to enhance taste. Place the strawberries in freezer containers or zip-top bags.
 
Blueberries also can be frozen for up to a year. Because their texture changes during freezing and storage, they may not be suitable for serving as you would fresh berries. For best results, wash blueberries thoroughly and place them in freezer containers or zip-top bags.
 
Raspberries freeze very well. Wash them gently so they maintain their delicate shape and then pat them dry with a paper towel. Arrange them in a single layer on a flat pan or cookie sheet and place them in the freezer. Once frozen, transfer the berries to a heavy plastic bag and return them to the freezer, where they will keep for up to one year.  
 
Source(s):
About.com "Strawberry Facts, Selection, and Storage"
Strawberry-recipes.com "Easy Recipes to Freese Strawberries"
Missourifamilies.org "Selecting Blueberries"
Whfoods.com "Raspberries"