I just use these with threaded knurled M3 - .5 knobs from Amazon.
http://www.thingiverse.com/thing:1001405
I never trusted the binder clips in terms of running into them with the print head. Glass is very versatile. You can glue it, hairspray it, apply tape to it... etc. What I like about it the most is that you yank the plate as soon as the print is complete and place another plate in the printer and you are back up printing in minutes while the other print cools. When cool they release themselves with no yanking around inside the printer. I rarely have to level my bed because I am not putting any stress on it whatsoever.