Importing CSV files
- Create a custom CSV file, or export the address book from your other webmail provider or email client as a CSV file.
- Sign in to Gmail.
- Click Contacts (located below your list of views) on any Gmail page.
- From the More actions dropdown menu, select Import....
- Click the Choose File button and locate the CSV file you'd like to upload.
- Select the file and click the Import button.
- Once you've successfully uploaded the document, Gmail will display the number of contacts imported.
- If some entries aren't included in your Contacts list, Gmail tells you why these entries were left out.
- If you receive error messages when attempting to import your contacts, you may need to edit your CSV file.
This solution is taken from the Gmail Help Center: http://mail.google.com/support/bin/answer.py?hl=en&answer=14024