Anything idiot proof I can attach to reliably hold small speakers (under 10" front to back)? Middle of the floor just doesn't cut it! It looks tempting along this line. Not that I'd know... http://www.fullcompass.com/product/...eps&utm_medium=shopping&utm_campaign=googleps
Something like that should be fine, you may find that your speaker manufacturer has their own mounts that may make things look a little nicer, as for mounting them to plasterboard, I usually use these (Rawplug Spring Toggle's) along with washers for heavy things like TV's or these (Metal Self Drill Rawplugs) for lighter things like bookshelf speakers etc.
I have a similar project, I want to mount small speakers on the ceiling. I wish to have their inclination adjustable, still trying to find out a good solution.
depends on your speakers. take a picture of the back of them and i'll help you out (used to install HT)