Add '#multicolumn' property to the form element checkboxes and radios to make checkboxes and radios display in columns.
UsageIn the definition of form element checkboxes/radios, add the '#multicolumn' property:
<?php
$form['my_checkboxes'] = array(
'#type' => 'checkboxes',
'#multicolumn' => array('width' => 3, 'minimum height' => 10),
.
.
.
);
$form['my_radios'] = array(
'#type' => 'checkboxes',
'#multicolumn' => array('width' => 5),
.
.
.
);
?>
The 'width' parameter is required, the 'minimum height' parameter is optional and it's used to keep column from looking "short/flat" and using fewer columns to keep column to the specified height.
See README.txt on how to override css to adjust different column width.