Have the same problem and saw a post a few post below this one about deleting photos from the gallery.Haven't tried it myself yet.
Also, if you open a compressed file (like a jpeg image) and re-save it, it gets compressed a second time. This reduces file size, but at a cost in terms of image quality. Not sure if this is actually the size-savings Fred discovered...
Becoming a subscriber on the site is the only way of doing that and it costs about the same as a cup of coffee a month.