sajidhussain

Instead of asking for both an email and a username on registration, this plugin lets you ask for email only, and uses that as username as well. Since the password is automatically generated and emailed to the user, this allows for sign-up form with a single form field: email.
For users that registered with different username and email address before this plugin was installed, their username and email address will be interchangeable on login.
The plugin offers a shortcode, [NP-registration], to add the registration form to a post or page.
Note: This plugin has not been tested with WP versions older than to 3.1.5. It should work with some older versions, but we can not guarantee it. However, if you are running an older version of WordPress, there are some very compelling arguments why you should consider upgrading. If you need help, there is plenty of free help to be found on WordPress.org, and Next Page, the authors of this plugin, offer a paid WordPress maintenance service.

Login Tweaks by Next Page

Use email as username to allow for single-field signup. Adds shortcode for adding registration form to post.

Nico Graff

This plugin offers you an easy way to let people sign up for your event. Just write a post what your event is about and add a shortcode to display the next date(s) people can sign up for.
A short and no fluff registration form will be displayed. After the registration an email with all the relevant information will be send to you and the person who signed up. That’s it.
Features
<ul>
<li>Simple – minimal setup, no external services neccessary</li>
<li>Display multiple dates for any event</li>
<li>Hides the event date automatically when the event is over</li>
<li>Shows a message when there are no dates at the moment</li>
<li>You can manually close the registration to any event</li>
<li>Decide for yourself how how to collect fees for your event</li>
<li>Show/hide fields in the registration form</li>
<li>Customize the “thank you” email</li>
<li>Add custom information to any event that will be added to the “thank you” email</li>
</ul>

WP Simple Events

Simple Event Registration Plugin. Create your event, seminar, course, training or meetup and let people sign up.

Login Tweaks by Next Page vs WP Simple Events