I spent most of the last week experimenting with water and I got a functioning directional water propagation, which is important, because without it controlling of water flow is hard. And I got these:
The buckets will be made of copper (iron rusts too easily).
The remaining problem is that on the phone chunk updates take a long time, and this is very noticeable on my Omnia 7. So initiating water flow will make the game run very slowly for a short time until the water ends spreading. I need to have a closer look at it whether I can make it run faster. I don’t expect miracles though.
Anyway, you can make your own swimming pool now.