The idea is simple- Build a series of 10 inch mortars around the wedding site at a safe distance from the guests. Use a standard combination of fuse, explosive powder, and wadding. As a payload, add several pounds of flowers (roses, baby's breath, etc.) with the stems and thorns removed for safety. Employ several drinkin' buddies to set off the mortars at a predetermined time in the ceremony ("I Do" then BOOM!). Mortars should be placed and aimed so that the semi-pulverized flower petals rain down on the ceremony. Electronically controlled fuses can be added to increase safety and allow for better choreography.

Relatively inexpensive, and mostly biodegradable. I plan to evenly distribute about a ton of flower petals over a half acre, but you can see how the quantities, placements, and payloads can be easly varied to achieve the desired effect.