The all emcompassing stick all wonder goo. Saves you from explaining to landlords, can also serve as silly putty in a pinch.

typically used to stick posters to walls, but can also be used to hold small objects down. remains sticky for an alarmingly long time..

The brand name version (possibly all versions, I am not sure as it has been a long time since i had to buy more, my ball is still sticky) is BluTack.

Manufacturer is Bostik. Comes in flat cardboard packages. Best way to remove is roll,roll,roll.


thanks to simonc.