Yes. Paint them.
And make a mosiac if they're small enough. If larger, make a walkway or use as stepping stones. Or you could make square pots out of them. Use pebbles in the bottom for drainage or drill a single hole in the middle. I can thing of more ideas if you'd like. I think the little pots sound the cutest.

I recently got a bunch of marble scrap from a local shop here in town, and I'm using it for all sorts of things..
I don't know how big your pieces are, but I'm assuming they're one foot squares, for flooring? here's some of my ideas...

- use them around water features, all marble looks great wet
- use them as stepping stones (good idea Walnut!)
- depending on how thick they are, maybe use them on a waterfall
- make a mini-table for your garden, or inside, using one tile as the tabletop, with maybe tall candlesticks or terracotta pots or chair spindles for legs
-use one square as a heat pad next to your stove, use it to put hot pots or bowls on to protect your countertop (if it already matches your floor or countertop, then even better!)
- use the extra in your garden, lay them under potted plants to give a little bit of extra "eye-catching"
- like Walnuts said (previous post) any type of mosaic would be great! especially if they're little tiles.. or if they're larger tiles, wrap the tiles in a towel and hit once or twice with rubber mallet (a hammer will give off too many little shards and dust) and keep checking and hitting until the pieces are small enough for mosaic work
- use as edging in your garden, as opposed to brick or stones, just use a glass scourer to run a line where you want the tile to break, then grasp both sides with a towel (if you're strong enough) or rubber edged pliers to get a clean line...

check in the craft department at WalMart or your local tile/craft shops, they have all sorts of tile tools and info

hope some of this helps!! :)

This is not meant as a criticism of anyone's ideas, but wouldn't marble make a very slippery stepping stone when it's wet? Are we talking smooth, polished marble? Just a thought.