I had a lovely toad in my garden for about 3 years, and he kept the slugs down a treat. Sadly, he hasn't shown himself this year so I suspect he's gone to the dark, damp corner in the sky :'(
I used to put out a shallow dish of water with a flat stone in it, when it was hot, and often found him lounging in it. I even managed to get a couple of photos, once :)