Ever driven by an ugly field or an empty part of your property and though "flowers would be so lovely here" - well, here is your chance (actually, next spring would be better) to make it happen. They are called Flower Grenades.
The "grenade" is made of clay and full of flower seeds. The clay will dissolve in the rain and in a month or so you should see some wild flowers.
Although this seems fun and throwing them into vacant lots seems harmless....I recommend you keep the "bombing" to your own property...just to be safe :)
These are from the UK - but you can get them here in the US through Amazon.