A panels content plugin for displaying some text and an image.

welcome_text_search_form.inc

<?php

/**
 * @file
 * Welcome text and search form content plugin.
 */
$plugin = array(
  'title' => t('Welcome text search form'),
  'single' => TRUE,
  'category' => array(t('Content widgets'), -9),
  'render callback' => 'welcome_text_search_form_render',
  'edit form' => 'welcome_text_search_form_edit_form',
);

/**
 * Render callback for the custom content type
 */
function welcome_text_search_form_render($subtype, $conf, $args, $context) {
  $block = new stdClass;
  $block->title = NULL;
  $output = '';
  $image = file_load($conf['image']);
  $image_uri = (!empty($image)) ? file_create_url($image->uri) : '';
  $form = drupal_get_form('search_block_form');

  // Compose HTML markup
  $output = '<div class="welcome-text-search-form" style="background-image:url(\'' . $image_uri . '\');">';
  $output .= '<div class="highlight-box"><p class="blurb">' . $conf['text'] . '</p>';
  $output .= render($form);
  $output .= '</div></div>';
  $block->content = $output;
  return $block;
}

/**
 * 'Edit' callback for the content type.
 */
function welcome_text_search_form_edit_form($form, &$form_state) {
  $conf = $form_state['conf'];
  // I stole this line from fieldable panel panes.. seems like we need it for
  // the managed file form element.
  ctools_form_include_file($form_state, $form_state['plugin']['path'] . '/' . $form_state['plugin']['file']);

  $form['text'] = array(
    '#type' => 'textfield',
    '#title' => t('Welcome text'),
    '#size' => 60,
    '#description' => t('Text that is displayed with the search form'),
    '#default_value' => !empty($conf['text']) ? $conf['text'] : '',
    '#prefix' => '<div class="clear-block no-float">',
    '#suffix' => '</div>',
  );
  $form['image'] = array(
    '#title' => t('Image'),
    '#type' => 'managed_file',
    '#description' => t('The uploaded image will be displayed as the background for the content.'),
    '#default_value' => !empty($conf['image']) ? $conf['image'] : '',
    '#upload_location' => 'public://content_widgets/',
  );
  // If there is already an uploaded image display the image here.
  $image_fid = (!empty($conf['image'])) ? $conf['image'] : NULL;
  if ($image_fid) {
    $image = file_load($image_fid);
    $form['image_preview'] = array(
      '#markup' => theme('image_style', array('style_name' => 'thumbnail', 'path' => $image->uri)),
    );
  }

  return $form;
}

function welcome_text_search_form_edit_form_submit($form, &$form_state) {
  // Save text
  if (!empty($form_state['values']['text'])) {
    $form_state['conf']['text'] = $form_state['values']['text'];
  }
  // Save image
  if ($form_state['values']['image'] != 0) {
    // The new file's status is set to 0 or temporary and in order to ensure
    // that the file is not removed after 6 hours we need to change it's status
    // to 1. Save the ID of the uploaded image for later use.
    $file = file_load($form_state['values']['image']);
    $file->status = FILE_STATUS_PERMANENT;
    file_save($file);

    // Manage usage count
    file_usage_add($file, 'library_content_widgets', 'welcome_text_search_form', 1);

    $form_state['conf']['image'] = $form_state['values']['image'];
  } elseif ($form_state['values']['image'] == 0) {
    // Retrieve the old file's id.
    $fid = ($form_state['conf']['image']) ? $form_state['conf']['image'] : NULL;
    $file = $fid ? file_load($fid) : FALSE;
    if ($file) {
      // When a module is managing a file, it must manage the usage count.
      // Here we decrement the usage count with file_usage_delete().
      file_usage_delete($file, 'library_content_widgets', 'welcome_text_search_form', 1);

      // The file_delete() function takes a file object and checks to see if
      // the file is being used by any other modules. If it is the delete
      // operation is cancelled, otherwise the file is deleted.
      file_delete($file);
    }
  }
}