I am slowly breaking down the molecular structure of a small portion of Blu Tack that I have been kneading since Christmas. When rolled into a sphere the Blu Tack is smaller than a pea, but bigger than a ball bearing. Thus, Blu Tack > Ball Bearing and Blu Tack < Pea. I hope this gives you some idea of the sort of scales we're talking about here. If I take my pencil and use it like a rolling pin on the Blue Tack I can flatten the blue stuff to roughly 2cm by 2cm. whilst the Tack is rolled out on my desk I find it fun to pummel it using the flat end of a pencil.
When rolled consistently between my forefinger and thumb it doesn't take long for the Blu Tack to become sticky. Once warm enough it goes all weird and starts to deposit small amounts of Blu Tack residue on your fingers and go a bit furry. I find it best at this point to roll it between two pieces of paper and really have a go at the molecular structure of the Tack. To prolong the agony for the Tack I will eventually cease my continual and persistent kneading and allow it to cool. Then five minutes later I'm at it again. I just can't get enough of it.
Also, when the Blu Tack has become malleable to a very high degree it is possible to spread it across a hard surface like it is Dairylea or something.