A CodePen by Yogev Ahuvia. A Circular Form - This interface experiments with user input by implementing a circular form, that rotates as the user advances through it's path.

index.html

<div class="wrapper">
  <div class="wheel closed">
    <form onsubmit="return false;">
      <ul>
        <li>
          <label class="sent-label">Thank You!</label>
          <input placeholder="Hi there! Press Tab..." tabindex="1">
        </li>
        <li>
          <input placeholder="This is," tabindex="2">
        </li>
        <li>
          <input placeholder="a circular form!" tabindex="3">
        </li>
        <li>
          <input placeholder="It lets you input data," tabindex="4">
        </li>
        <li>
          <input placeholder="or just read a list," tabindex="5">
        </li>
        <li>
          <input placeholder="through a path." tabindex="6">
        </li>
        <li>
          <input placeholder="When ready," tabindex="7">
        </li>
        <li>
          <input placeholder="press Enter to Send." tabindex="8">
        </li>
      </ul>
      <input type="submit">
    </form>
  </div>
</div>

script.js

function setWheelRotation(rotation) {
  $('.wheel').css('transform', 'rotate('+rotation+'deg)');
}

function onSubmit() {
  $('.wheel').addClass('sent');
  setWheelRotation(697.5);
  setTimeout(function() {
    $('.wheel').removeClass('sent');
    $('input').val('');
    firstInputField().focus();
  }, 5000);
  return false;
}

function firstInputField() {
  return $('.wheel li:first-child > input');
}

$('form').on('submit', function() {
  onSubmit();
});

$('input').on('focus', function() {
  var index = $(this).parent().index();
  var rotation = -22.5 - (45 * index);
  setWheelRotation(rotation);
});

var lastTabIndex = $('[tabindex]').length;

$('[tabindex]').on('keydown', function(event) {
  if (event.keyCode == 9) { // Tab pressed
    event.preventDefault();
    var currentElement = $(this).get(0);
    var curIndex = currentElement.tabIndex;
    if (event.shiftKey) {
      if (curIndex == 1) {
        return;
      } else {
        curIndex--;
      }
    } else {
      if (curIndex == lastTabIndex) {
        return;
      } else {
        curIndex++;
      }
    }
    
    $('[tabindex='+curIndex+']').focus();
  }
});

$(document).ready(function() {
  $('.wheel').removeClass('closed');
  firstInputField().focus();
});

style.scss

@import "compass";
.wheel {
  width: 500px;
  height: 500px;
  top: 30px;
  left: 50%;
  margin-left: -250px;
  border-radius: 100%;
  position: absolute;
  transition-delay: 0s;
  transition-property: transform;
  transition-duration: 0.5s;
  transition-timing-function: ease-in-out;
  transform-origin: 50% 50%;
  transform: rotate(-22.5deg);
  
  button.submit {
    font-family: 'Open Sans', sans-serif;
    outline: none;
    display: block;
    color: #eee;
    font-weight: 300;
    position: absolute;
    width: 100px;
    height: 100px;
    border-radius: 100%;
    border: 0;
    background: #222;
    box-shadow: 0px 0px 3px rgba(0,0,0,0.3);
    z-index: 100;
    left: 50%;
    top: 50%;
    margin-left: -50px;
    margin-top: -50px;
    transition: opacity 1s, box-shadow 0.3s;
    pointer-events: none;
    opacity: 0;
    
    &:hover {
      box-shadow: 0px 0px 10px rgba(255,255,255,0.5);
    }
    
    &:focus {
      opacity: 1;
      pointer-events: auto;
    }
  }
}

@mixin slice-background($lighten) {
  @include filter-gradient(lighten(rgb(20,177,144),$lighten), #ffffff, horizontal);
  @include background-image(linear-gradient(45deg, lighten(rgb(20,177,144),$lighten) 178px, rgba(255,255,255,0) 179px));
}

ul {
  margin: 0;
  padding: 0;
  
  > li {
    width: 250px;
    height: 250px;
    margin: 0;
    padding: 0;
    list-style-type: none;
    display: block;
    position: absolute;
    top: 0;
    left: 0;
    border-top-left-radius: 250px;
    border-top-right-radius: 0px;
    transform-origin: 100% 100%;
    pointer-events: none;
    transition-delay: 0s;
    transition-property: transform;
    transition-duration: 3s;
    transition-timing-function: ease-in-out;

    &:nth-child(1) {
      transform: rotate(0deg);
      z-index: 8;
      @include slice-background(0%);
    }
    
    &:nth-child(2) {
      transform: rotate(45deg);
      z-index: 7;
      @include slice-background(1%);
    }
    
    &:nth-child(3) {
      transform: rotate(90deg);
      z-index: 6;
      @include slice-background(2%);
    }
    
    &:nth-child(4) {
      transform: rotate(135deg);
      z-index: 5;
      @include slice-background(3%);
    }
    
    &:nth-child(5) {
      transform: rotate(180deg);
      z-index: 4;
      @include slice-background(4%);
    }
    
    &:nth-child(6) {
      transform: rotate(225deg);
      z-index: 3;
      @include slice-background(5%);
    }
    
    &:nth-child(7) {
      transform: rotate(270deg);
      z-index: 2;
      @include slice-background(6%);
    }
    
    &:nth-child(8) {
      transform: rotate(315deg);
      z-index: 1;
      @include slice-background(7%);
    }
    
    > input, > .sent-label {
      font-family: 'Open Sans';
      color: #eee;
      text-shadow: 1px 1px 1px rgba(0,0,0,0.3);
      outline: none;
      pointer-events: auto;
      display: block;
      position: absolute;
      top: 75%;
      left: 0px;
      width: 250px;
      border: 0;
      text-align: left;
      padding-left: 20px;
      background: none;
      transform-origin: 50%;
      transform: rotate(22.5deg);
    }
    
    > .sent-label {
      display: none;
      opacity: 0;
      font-size: 1.2em;
    }
  }
}

.closed {  
  li:nth-child(1) { transform: rotateX(0deg); }
  li:nth-child(2) { transform: rotateX(0deg); }
  li:nth-child(3) { transform: rotateX(0deg); }
  li:nth-child(4) { transform: rotateX(0deg); }
  li:nth-child(5) { transform: rotateX(0deg); }
  li:nth-child(6) { transform: rotateX(0deg); }
  li:nth-child(7) { transform: rotateX(0deg); }
  li:nth-child(8) { transform: rotateX(0deg); }
}

.sent {
  &.wheel {
    transition-delay: 0s, 3s;
    transition-property: transform, left;
    transition-duration: 1s, 0.5s;
    transition-timing-function: ease-in-out, ease-in;
    left: 150%;
  }
  
  .sent-label {
    display: block;
    transition: opacity 1s;
    opacity: 1;
  }
  
  input {
    pointer-events: none;
    transition: opacity 1s;
    opacity: 0;
    
    &::-webkit-input-placeholder { /* WebKit browsers */
      opacity: 0;
    }
    &:-moz-placeholder { /* Mozilla Firefox 4 to 18 */
      opacity: 0;
    }
    &::-moz-placeholder { /* Mozilla Firefox 19+ */
      opacity: 0;
    }
    &:-ms-input-placeholder { /* Internet Explorer 10+ */
      opacity: 0;
    }
  }
  
  li:nth-child(1) { transform: rotateX(0deg); }
  li:nth-child(2) { transform: rotateX(0deg); }
  li:nth-child(3) { transform: rotateX(0deg); }
  li:nth-child(4) { transform: rotateX(0deg); }
  li:nth-child(5) { transform: rotateX(0deg); }
  li:nth-child(6) { transform: rotateX(0deg); }
  li:nth-child(7) { transform: rotateX(0deg); }
  li:nth-child(8) { transform: rotateX(0deg); }
}

html, body {
  width: 100%;
  height: 100%;
}

body {
  font-family: 'Open Sans', sans-serif;
  font-size: 18px;
  font-weight: 300;
  background: #222;
  position: relative;
}

[type="submit"] {
  opacity: 0;
  pointer-events: none;
}

input {
  &::-webkit-input-placeholder { /* WebKit browsers */
    color: #eee;
    opacity: 1;
  }
  &:-moz-placeholder { /* Mozilla Firefox 4 to 18 */
    color: #eee;
    opacity: 1;
  }
  &::-moz-placeholder { /* Mozilla Firefox 19+ */
    color: #eee;
    opacity: 1;
  }
  &:-ms-input-placeholder { /* Internet Explorer 10+ */
    color: #eee;
    opacity: 1;
  }
}

input:not(:focus) {
  &::-webkit-input-placeholder { /* WebKit browsers */
    opacity: 0.4;
  }
  &:-moz-placeholder { /* Mozilla Firefox 4 to 18 */
    opacity: 0.4;
  }
  &::-moz-placeholder { /* Mozilla Firefox 19+ */
    opacity: 0.4;
  }
  &:-ms-input-placeholder { /* Internet Explorer 10+ */
    opacity: 0.4;
  }
}