There are many floorstanders that can disappear, but it requires a decent cabinet so they're normally not very inexpensive.
Relatively small speaker with a "big" performance: Role Audio Starship SE model
My review on the Role Audio Starship SE speaker just went up on the Stereo Times website. If you are looking for a floor-stander that's relative small, but delivers reference level bass extension, the disappearing act of a two monitor, beautiful timbres because of using all natural fiber based drivers, and quad transmission line technology, take a look at the review for the details on this excellent speaker.