The old pail with a pinhole has worked for years in my herp room. If you want to get fancy you can use a gravity or pump operated system with a horticultural drip emitter. You can pick them up for pocket change at your local hydroponic supplier. Most allow for drip rate adjustments and last almost forever.
Revenge is a dish best served cold...
With a side plate of steaming entrails,
And a nice Bordeaux!