Programmatically adjusting permissions

check out http://drupal.org/project/permissions_api

Any solution that works without a module?

The trick is look inside of drupal core functions for the pieces you need, then take them out and run them in a modules install file, or even once in your theme template.php file

Specifically, if you can practice some simple mysql queries, you'll find a lot of power to quickly do tasks.

/*
*
* Programmatically create a role in Drupal
*
*/
db_query("INSERT INTO {role} (name) VALUES ('%s')", 'ecoach');

/*
*
*  assign role to newly created user accounts
*
*/
// ge the role id number ("rid")
$rid = db_result(db_query("SELECT rid FROM role WHERE name = 'ecoach'"));


$query = db_query("SELECT uid FROM `users` WHERE `name` LIKE '%Edge Studio Voice Over Coach%'");
while ($uid = db_result($query)) {
	// check to make sure you are not adding role twice
        $count = (int)db_result(db_query("SELECT COUNT(*) AS COUNT FROM {users_roles} WHERE uid = %d AND rid = %d",$uid,$rid));
	
       if($count < 1) {
                // add role programmatically to user
		db_query("INSERT INTO {users_roles} (rid, uid) VALUES ('%d','%d')", $rid, $uid);
		
	}
	
// if you want to assign permissions to your role just add them as a comma separated list
db_query("INSERT INTO {permission} (rid, perm) VALUES (%d, '%s')", $rid, 'edit field_ecoach_feedback, edit field_my_secret_field');