Hey all,
I noticed a few threads where people were asking to be able to change the default w=320 h=240 when inserting a singlepic through the media manager thing.
I really wanted to change it myself too, but unfortunately there isn't an easy way of doing it. But if you really want to (if you're like me and you don't want to change it to a different size every time you insert an image) you can make a quick change.
in wp-content/plugins/nextgen-gallery/admin/ you can edit the media-upload.php file on line 46-47:
if ($image['size'] == "singlepic")
$html = "[singlepic id=$send_id w=320 h=240 float={$image['align']}]";
That's the line that makes the singlepic shortcode to be inserted into your post. If you just change the w and h to whatever you want, it will always default to that. Hope that helps a few people!
Mike