User Roles — Support — WordPress.com

Author – can write, upload photos to, edit, and publish their own posts.
Contributor – has no publishing or uploading capability, but can write and edit their own posts until they are published
Follower (public sites) / Viewer (private sites only) – can read and comment on posts and pages

http://en.support.wordpress.com/user-roles/

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Comments in WordPress Users must be registered and logged in to comment

Users must be registered and logged in to comment: This option will only allow registered users of your site to post comments.
Automatically close comments on articles older than _____ days: Closing comments on posts that are no longer active is a good way to limit spam comments. This option will do will allow your site to do this automatically.
https://codex.wordpress.org/Comments_in_WordPress

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WordPress Now Lets You Phone in Your Blog Posts

Automattic founder Matt Mullenweg announced the new feature for WordPress.com earlier today. It’s rather simple: enable “Post by Voice” in your dashboard and you will receive a phone number and a unique code for posting audio from your phone to your blog. You can post up to one hour of audio at a time.

http://mashable.com/2010/07/01/wordpress-phone/

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