<%= input large,
              prepend => { radio_button => ['yes'] },
              input => { text_field => ['username'] },
              append => '@'
    %>
    <div class="input-group input-group-lg">
        <span class="input-group-addon"><input name="yes" type="radio" /></span>
        <input class="form-control" id="username" type="text" name="username" />
        <span class="input-group-addon">@</span>
    </div>
A large input group with a radio button prepended and a string appended.
@
    <%= input input => { text_field => ['username'] },
              append => { button => ['Click me!'] },
    %>
    <div class="input-group">
        <input class="form-control" id="username" type="text" name="username" />
        <span class="input-group-btn"><button class="btn btn-default" type="button">Click me!</button></span>
    </div>
An input group with a button.