A great use for recycled glass is by making a mosaic project with it. There are all different kinds of projects you and the family can dive into, from smaller mosaic picture frames to a large mosaic tabletop.
When it comes to choosing your materials, pretty much any glass you intend to recycle or throw away will do. Beverage bottles in different colors and textures work well and old tiles or broken dishes are especially great because you can incorporate bits of pattern in your design. You can also check online for recycled mosaic glass -- products that come from recycled bottles or "waste" from stained glass manufacturers.
The glass will come in a variety of colors, shapes and sizes and are ground on the edges to make them safe for handling. Get your kids involved in all stages, from planning to execution, and explain to them along the way about the recycling process and how reusing materials is always better than disposing them.