The next time you have green onions, don't throw away the white ends. Simply submerge them in a glass of water and place them in a sunny window. Your onions will begin to grow almost immediately and can be harvested almost indefinitely. We just use kitchen scissors to cut what we need for meals. I periodically empty out the water, rinse the roots off and give them fresh water.
Easter basket for the man in your life or birthday gift! This could also be recreated at Christmas as a stocking. This is a cool idea because 1) it's rather inexpensive and 2) guys just don't care enough about stuff like this so it's perfect!