Another simple, often-overlooked device to rig up miniature explosions is the store-bought mousetrap or rat-trap (for bigger effects).

Simply secure the trap to the desk, table-top, shelf or other surface with nails, screws or heavy tape. Set the spring-loaded mechanism with a trip wire running offstage out of sight.

Place the (pre-broken) answering machine over the contraption and, on cue, the sound of an explosion can be heard while the trip-wire is activated. Voila! A very startling and violent eruption onstage.

You may need to experiment with the placement of the trap (or 2 or more if necessary) to get the right effect. (For example, you may want to nail the trap to a wood block instead of directly to the table-top to get it to the right height.)   A small container of talcum powder or corn-starch can also be set in place to substitute "smoke." And you will definitely need to remove most of the guts from the answering machine as the weight of the item becomes an issue.

We have used this simple technique to great effect "shooting" mugs off mantlepieces, knocking vases off tables, etc. etc.