I have one of those preformed plastic ponds, complete with preformed plastic waterfall, available at your local super store. Just finished building the waterfall part of it a nice enclosure, with enough room to plant some flowers around. Even got around to putting a couple different aquatic plants into the water. To date I have 4 lily pads above water, and a fifth one on the way!
One of the things I am very proud of is reusing a cheap stand alone fountain as the sprayer. It creates a nice looking effect to see the water gently gushing up and then falling down a two tiered fountain into the waterfall feature. However this morning I noticed that the water had stopped flowing, it appears that the tubing for the pump and the copper piping on the fountain no longer wish to hold hands and play nice.
Oh well, guess I need to make another trip to my local home and garden store for more supplies :)