Hi folx.
I figured out how to expand (and word-wrap) the very tiny description filed in the nextgen gallery uploader.
Open the file:
wp-content/plugins/nextgen-public-uploader/npu-upload.php
Find the Line:
$strOutput .= "\n\t<input type=\"textarea\" name=\"" . esc_attr( $name ) . "\" id=\"" . esc_attr( $name ) . "\"/>";
and replace it with this:
$strOutput .= "\n\t<textarea type=\"textarea\" style=\"height:150px;width:680px\" name=\"" . esc_attr( $name ) . "\" id=\"" . esc_attr( $name ) . "\"/></textarea>";
Now you have a resizable Text Field. :D You can change or add styles within "style" to your needs. For my needs height and width is enough.