Gravity Forms "is a full featured contact form plugin that features a drag and drop interface, advanced notification routing, lead capture, conditional logic fields and the ability to create posts from external forms." Simply it makes form creation easy, straight forward, and saves a ton of time. Furthermore, with their new hooks/filters documentation, 
Gravity Forms Releases PayPal & User Registration Add-Ons
Gravity Forms has a small body of Add-Ons and in their newest release they have added a user-friendly way to install and activate these add-ons. Two new add-ons were released today too: PayPal and User Registration Add-Ons. The PayPal Add-On allows you to accept PayPal payments through a Gravity Form, including donations and recurring payments. The User Registration Add-On allows you to create user registration forms which include BuddyPress and Multisite integration (including integration with the PayPal Add-On).
What Can Gravity Forms Do?
Gravity Forms can create Contact Forms, Support Forms, Surveys, Polls, Guest Post Submissions, and User Generated Content. And now with their newly updated hooks/filters documentation, other form types will be limitless!
When I purchased it, I only purchased it to get rid of the craziness of using other form plugins that were clunky and difficult to style to create a Contact Form, the most popular use of Gravity Forms. You can gather basic information like: name, date, time, Phone, Address, Website, Email, and even upload files, and all of this information is validated to ensure that the user has entered the correct information (validates emails, phone numbers, etc!). It also comes with reCAPTCHA compatability for spam protection. However, I have gone beyond that to create other types of forms including surveys, polls, guest post submissions, and user-generated content. I am now experimenting with other types of form creation (and will report back later) with the hooks that I found in the code. Now with the documentation, it will be much easier.
A few of the hidden great things about Gravity Forms is that it maintains a record of all submitted forms, ability to make notes on the submissions, email notes, conversion rate (# submitted/# viewed), and much more to come.
What's New in Gravity Forms v1.5
Multi-Page Forms
One of the most widely requested features is finally here, multi-page form capabilities. Using the new Page Break field you now have the ability split longer forms into multiple pages or steps. We have also integrated a visual paging status bar that can be used to show a progress bar or the steps involved in completing the form.
Pricing Fields
Pricing Fields allow you to create quotes and order forms. It features integrated pricing calculations and is compatible with the Gravity Forms PayPal Add-On. Pricing Fields consist of a Product Field, Option Field, Quantity Field, Shipping Field, Donation Field and Total Field. They allow you to easily turn your form into an order form and collect payments when combined with the PayPal Add-On.
Textarea Character Counter
Easily limit the number of characters entered into a textarea and include a visual character counter that lets them know how many characters are allowed and how many characters have been entered.
CSS Ready Classes
Easily create multi-column layouts using built in CSS classes. These keywords are custom CSS classes you add to the CSS Class Name option under the Advanced tab for each field. Using our pre-defined CSS class names you can easily create 2 or 3 column forms, display radio button and checkbox options in 2, 3 or 4 columns as well as turn a Section Break into a scrolling text field.
Default Notification
Gravity Forms will now automatically setup an Admin Notification that uses the WordPress Admin email as the Send To and includes all submitted form fields when a new form is created.
Post Field Enhancements
We have enhanced the content template capabilities of the Post Fields and extended them to the Post Custom Field. Now you can use the content template capabilities on the Post Title, Post Body and Post Custom Fields in the form builder. The Post Category field has been enhanced to allow for an initial placeholder value (ex. "Please Select a Category") and now supports Admin Only visibility to allow you to set a default category using the Post Category field.
Checkbox and Multiple Choice (Radio Button) HTML Support
The Checkbox and Multiple Choice (Radio Button) fields now support HTML in the option labels. This allows you to include links or use images as your options.
Shortcode Support
Love using Shortcodes? Need to insert custom code into the Email Notification, Confirmation Text or HTML Field content? Gravity Forms now supports utilizing Shortcodes in the Email Notification Message Body, Confirmation Text and within the content of an HTML Field.
Enhanced Bulk Edit Functionality
You can now reset views, or delete entries from the Edit Forms screen using enhanced options added to the Bulk Edit functionality.
New Hooks and Filters
We have added a variety of new hooks and filters, all of which are documented (with examples) in the brand new Documentation area of the support site.
Upgrade and Renewals
Now you can Upgrade or Renew your Gravity Forms License Key right from your WordPress Dashboard! Visit either the Settings page or the Update page. If an Upgrade is available, or you are within the Renewal period, you will be presented with options to purchase the Upgrade or Renewal.
Support For New Add-Ons
Gravity Forms v1.5 supports the introduction of the PayPal Add-On and User Registration Add-On which are now available for Developer License customers.