I am not sure if you have any marbles left, but I just redid my kitchen decor with marbles. It started off as a bud vase filled with marbles and a taper candle.. and then I went crazy.
I used premixed tiling mud to cover my plain glass canisters with marbles.
I poured the mud into a foil pan (later removed) and added marbles for a hot plate (too pretty to actually use).
I hot glued the marbles around my cork board.
My centerpeice is small glass bowls and cups filled with marbles and tealights.
May sound odd, but I picked out all the variations of blue, green, cream, and iredescent marbles from my kids' stash of marbles and my kitchen looks great. And yes, you can still buy marbles.. Walmart sells them in tins for around $3.