In response to google's decision to gather information on its gmail customers, one response might be to alert your contacts and delete your gmail account, going to another email provider.

To delete your gmail (and all your contacts):

Go to Google Account Settings.
(under your log in)

Follow the Edit link next to My products.

Click Remove Gmail permanently under Delete a Product.
You can also choose Close account and delete all services and info associated with it to remove your entire Google account (including your search history, Google Docs, iGoogle page, AdWords and AdSense as well as other Google services).