There're three kinds of files in this Clipart library:
#1. jpeg (it seems that they're these files you want to "extract")
#2. hpi (think of it as image with alpha channel)
#3. pdf (here, vector cliparts)
I use two different ways to do what you're looking for:
#1. importing the whole Clipart folder in iPhoto:
As iPhoto can't import pdf and hpi files, you'll get all jpeg files from the BeLight Clipart library in a iPhoto "event".
#2. using iMedia Browser (a nice and free tool from Karelia: http://www.karelia.com/imedia/)
The same way, dragging the Image folder (/Library/Application Support/BeLight Software/Clip Art/Images/) onto the iMedia Browser panel, creates a "folder alias" with all jpeg files (2058 files from the whole library).
Note that unlike iPhoto, iMedia Browser doesn't copy files, it creates reference/alias to the folder/files.
Btw., apart from using Image Tricks, the only other application that can open hpi files seems to be Graphic Converter.
Hope this helps.