In a fit of domesticity a few weeks ago, I planted some Paper Whites (narcissus) in glass vases to add some greenery to the house this winter.
It's a really simple exercise and as the bulbs sprout really quickly, very rewarding too.
Just place the bulbs in a glass container on top of a layer of pebbles and add water until it just reaches the bottom of the bulbs. Don't add too much or they will rot. Then store the container in a dark cupboard, checking the water level regularly. Once you see green shoots (this should take a week to ten days), remove the container from the cupboard and place in a spot where they will receive morning sunlight. Once flowers start to appear, you can move the container indoors and display.
Just make sure to carry on topping up the water levels. You can also add some cut flower food to the water to keep it fresh.
Not all bulbs can grow in water alone, the best varieties are Paper Whites, Tulips, Crocus, Hyacinths and Amaryllis.
Go here to find a more detailed description on how to go about planting bulbs hydroponically.