Have been playing with 'Contaires' teaser.module and thought I should report how I managed to install and implement it.
First, the install doesn't have a teaser.mysql to support the modifications to the node table required for the module to function. You need to modify the table "node" and add the following six columns
teaser_title varChar(100)
teaser_link varChar(100)
teaser_weight tinyInt(4)
teaser_image varChar(255)
teaser_image_width tinyInt(6)
teaser_image_height tinyInt(6)
or in MYSQL
ALTER TABLE `node` ADD `teaser_title` VARCHAR( 255 ) NOT NULL ;
ALTER TABLE `node` ADD `teaser_link` VARCHAR( 255 ) NOT NULL ;
ALTER TABLE `node` ADD `teaser_weight` VARCHAR( 255 ) NOT NULL ;
ALTER TABLE `node` ADD `teaser_image` TINYINT( 4 ) NOT NULL ;
ALTER TABLE `node` ADD `teaser_image_width` TINYINT( 6 ) NOT NULL ;
ALTER TABLE `node` ADD `teaser_image_height` TINYINT( 6 ) NOT NULL ;
Having done this the module installs successfully and users can now add nodes with extra teaser information.
Second, I then modified the module slightly so that the drupal coulmn node.teaser was also made visible as part of the node editing window. This will then allow you to modify the teaser text that drupal creates as standard - drupal chops first X chars of the content and puts that into the teaser field, but for our implementation we needed to have a customised input. I have altered the function "teaser_nodeapi", the changed function is listed below: