Birthday Box was built to manage the birthdays of all of your friends, get reminders on their birthday, and the ability to wish happy birthday to them using facebook, text messaging, mail, email, and more.

The current version has been designed for Android 1.5 and 1.6, however it should work for 2.0+

Screenshots:

See all birthdays, or approaching birthdays:

Say happy birthday in different ways to friends who already have contact information on your phone:

Retrieve all of your friends  birthdays from Facebook: