  A configuration of pebbles on the vertices of a graph is solvable if one can
place a pebble on any given root vertex via a sequence of pebbling steps. A
function is a pebbling threshold for a sequence of graphs if a randomly chosen
configuration of asymptotically more pebbles is almost surely solvable, while
one of asymptotically fewer pebbles is almost surely not. In this note we show
that the spectrum of pebbling thresholds for graph sequences spans the entire
range from n^{1/2} to n. This answers a question of Czygrinow, Eaton, Hurlbert
and Kayll. What the spectrum looks like above n remains unknown.
