I have 2 big pallets (about double the size of normal pallets and well made) from when Habitat delivered some kitchen stuff to us, 2 normal pallets from random things when our house was being extended, 2 from Sainsburys that I... erm, aquired, then a load of concrete blocks i made a mould for and used up some old concrete mix we had lying around. Then a big, hardwood log that was found on the beach near Brighton and stayed at my grandparents house for 5+ years, then we trailer'd it back to mine.