I just spent a good 30 minutes figuring this out, so I thought I would post just in case anyone out there is having a similar mental block. 🙂
To create a BuddyPress 1.2 child theme, simply create a new folder in your normal “wp-content/themes” folder and then put a style.css file into that folder with the following code at the top:
/*
Theme Name: YOUR THEME NAME HERE
Theme URI: http://buddypress.org/extend/themes/
Description: YOUR THEME NAME HERE based on default 1.2 theme for BuddyPress.
Version: 1.2
Author: BuddyPress.org
Author URI: http://buddypress.org
Template: bp-default
*//* Layout styles for home page, internal pages and blog/directory pages */
@import url( ../../plugins/buddypress/bp-themes/bp-default/_inc/css/default.css );/* Default theme admin bar styles */
@import url( ../../plugins/buddypress/bp-themes/bp-default/_inc/css/adminbar.css );
thanks man