Slugs and snails - good news, bad news
First the bad news - On one of my newly discovered British garden shows the host claimed that slugs and snails, in their short lifespan, can produce 60,000 progeny. In addition, snails have great homing instincts, so if you fire them over the fence into your neighbour's yard, they will find their way back. That's cetainly reassuring.
The good news - a magazine article about cucumbers claims - "Are grubs and slugs ruining you planting beds? Place a few slices of cucumber in a small aluminum pie tin. The chemicals in the cucumber react with the aluminum to emit a scent that is undetectable to humans but drives garden pests crazy and makes them flee the area."
Sounds like an interesting idea, worth a try.