Instead of submiting an entire post, is there any way to submit a lite-post or a simple message?

I was wondering if there is a way or a plugin to post something like twitter update messages instead of a post.

Something like http://p2demo.wordpress.com/ but better, where a user will post update messages not an entire post (in database matters). That means you will save space, make it quicker and fewer database resources.

I am looking for a way to post lite messages, that database will only save the must, like IDs, title, post and a thumb, through php maybe. No taxonomies and and and.

I hope you understand what I am trying to say (sorry for any bad English)

Thank you.

Updated: I found this code, should I use this as a twitter posting feature? (As I said I need fewer db resources)

// Create post object
$my_post = array();
$my_post['post_title']    = 'My post';
$my_post['post_content']  = 'This is my post.';
$my_post['post_status']   = 'publish';
$my_post['post_author']   = 1;
$my_post['post_category'] = array(0);
// Insert the post into the database
wp_insert_post( $my_post );"