Most handheld computerized address books hold an entire contact database, close at hand, annotated and searchable.  Every contact entry can include name, address, specialty, multiple phone numbers, email address, custom fields, and notes.

Users can search by keyword, name, specialty, practice group, city, or notes text.  A paper-based address book is cumbersome and often not nearby when needed. Phone numbers change frequently, and handwritten changes are often hard to decipher.