tricks to keep filament spooled

Well I can't provide a pic as I have recently changed my setup, but what I was using before was a cotton pad, (you know those little circular pads women use for cleaning off makeup), that I would fold over in half around the filament. Then I would use one of those little black paper clip things that IanJohnson was using to hold his glass to the bed to hold the edges of the cotton pad together so that the cotton pad was "taco-ing" the filament. Then I used some string that I put through the metal finger tabs on the metal clip. Then I used magnets to hold the string ends to the backside of the printer to make sure the metal clip and cotton pad wouldn't slide around anywhere. The filament could still slide through the pad just fine and kept it from unwinding. Hope that made sense. I have found that sometimes I need to unspool the filament and then respool as for whatever reason the filament came wound pretangled, (the filament was wound under the previous loops).

My thingiverse design for this issue.
http://www.thingiverse.com/thing:38222

This helped me a lot, plus you can add the sponge to it to wipe the dust off the filament.  I also use a little spring hair clip that I have next to the spool to keep it under the slightest tension so it doesn't overspin.  I have the original spool holder design that came out perpendicular to the back of the machine.

How does it flop off, does the spool itself move so it's pulling on an angle, or does a quick tug by a y-axis movement keep spinning the spool until there is an overspin causing filament to come loose?

In either case, using the clip that I mentioned to keep tension against the side of the spool would prevent both of those issues. 

I have an idea for a tension clip that people could use, let me draw something up.

The filament wants off my octave spool like its a prison break.  I believe that when it does popoff, it is due to over rotation of the spool itself.

lawsy's Filament Guide Valve works great for me to stop spool unwinding and tangle issues. I use it for Solidoodle, Octave, Ultimaker, and printed spools... http://www.thingiverse.com/thing:31317

Very low tech... Very effective though.

Here's a couple of photos showing my setup and the reel holder I built to hang from the shelf above the printer. The PVC pipe is not glued so it's easy to take apart. This cabinet was a wardrobe cabinet I purchased from Menard's and modified a bit. Used it as a modeling worksite for a number of years and converted it to use for the Solidoodle. There was another shelf that I removed.

I'm using a modified SD spool mount which raises the spool and turns it 90 degress. 

I am using Octave filament and just made some large diameter cardboard discs (with holes for the spool rod to go thru) about 9" in dia. that I press against the sides of the spools using split spool locator rings (that fit on the spool rod.) that I printed.

Now it doesn't seem to matter if the filament unspools a little as it can't really go anywhere.