Hercules GS401BB Mini Folding Acoustic Guitar Stand
This has to be the smallest stand yet. It folds away into a space about the size of a couple of effects pedals and comes complete with a carry bag. It's obviously ideal when space is at a premium, but is strictly for electrics and thinner-bodied acoustics like the Yamaha APX series. The guitar just sits in it with its back supported by a foam pad, but the three-pronged heavy-duty horizontal base means that the stand is very difficult to top over.