Daily entries from the 17th century London diary
You can receive each day's diary entry via email by visiting the subscription form and entering your email address. Emails are sent daily, a few hours after the diary entry appears on the site. Annotations are not included but there will be a link to them.
There are a variety of RSS feeds available for different parts of the site. You can use these with a reader like Google Reader and the latest posts will appear automatically for you.
The @samuelpepys Twitter account updates several times a day with excerpts from that day's diary entry.
Aimer Media have made an App which you can buy in the iTunes Store, which will let you read the diary a day at a time, or more if you like.