Gardening Via the Grocery Store

• separate out a garlic bulb into cloves and plant them
• use the tops of the green onions/shallots/leeks/etc, leaving 3-4" of the bottom, and plant the bottoms
• basil readily roots from cuttings (aka the fresh herb packs), and a lot of other herbs will too
• plant pepper seeds, this works best if you buy a yellow, orange or red pepper - green peppers are under-ripe and the seeds are less viable 
• you can also plant seeds from tomatoes, squash, cucumbers, eggplant... and other things with seeds
  you will get a better result if you use seeds from heirloom/non-hybrid veggies as some hybrid seeds won't fruit at all while others will give you a different fruit than the parent
• if your onions or potatoes bolt in the cupboard you can plant them

Other ideas?