Here's an example from Austin Matzko
$post_ids = array(0);
foreach( array(1, 2, 3, 4, 5, 6) as $cat_id ) {
if ( $posts = get_posts(array('cat' => $cat_id, 'showposts' => 5)) ) {
$first = array_shift($posts);
$post_ids[] = $first->ID;
}
}
query_posts(array('post__in' => $post_ids));
Then here's another example:
<?php
//for each category, show 3 posts
$cat_args=array(
'orderby' => 'name',
'order' => 'ASC'
);
$categories=get_categories($cat_args);
foreach($categories as $category) {
$args=array(
'showposts' => 3,
'category__in' => array($category->term_id),
'caller_get_posts'=>1
);
$posts=get_posts($args);
if ($posts) {
echo '<p>Category: <a href="' . get_category_link( $category->term_id ) . '" title="' . sprintf( __( "View all posts in %s" ), $category->name ) . '" ' . '>' . $category->name.'</a> </p> ';
foreach($posts as $post) {
setup_postdata($post); ?>
<p><a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title_attribute(); ?>"><?php the_title(); ?></a></p>
<?php
} // foreach($posts
} // if ($posts
} // foreach($categories
?>