Effort: MinimalCost: Free
Most folks have accumulated a handful of e-mail addresses that they are not prepared to stop checking altogether. If you're a Gmail user, Google's e-mail app is particularly adept at consolidating several e-mail addresses so that you don't have to log in to five different accounts every day. You can either set up your other accounts to forward all incoming mail to your Gmail account or use Gmail's "Get mail from other accounts" feature to automatically import every message you receive to your centralized inbox. Gmail even permits you to use it to send e-mail on behalf of your other, non-Gmail addresses.
If you prefer to do things the Microsoft way, Microsoft Windows Live Hotmail offers much of the same functionality as Gmail, but in an interface that's the spitting image of Outlook.