How to keep snails and slugs off a raised fruit/veg bed - DIY

Well ... after making a raised flower bed and filling it with lovely fruit and veg, the snails and slugs found it in under two weeks and managed to snack on most of it in a few nights! Looking on the web all remedies apart for dodgy pills and slow killing parasites fail to work, but I had a bit of a thought ....
Wire wool ,,,

All you need is wire wool and tacks, total cost £2.33

 Unroll the wool, divided it into two strips and tack it all around

When you've finished, bunch it up either side of the tacks to make a prickly fence and your done!

Proof that it works ... notice 3 sneaky snails all facing away after failed attempts at getting in!

Well there you go, it worked and pretty eco! Might even work if you put it round fruit and veg on the ground ... Nice!