In a related idea, running water on a shallow surface can be used to attract hummingbirds too. I'm not sure how I'd get that setup just yet, but it's an idea I'll tuck away for future investigation. For right now I'm thinking maybe an in-tank water filter (like the kind we have in the turtle tank), buried in rocks in a slightly deeper container with water. I think the rocks above the surface will work the same as the shallower plane for the insect waterer, and the filter will keep the water clean and moving. I wonder if I make the dish wide enough if it could function as both the moving waterer for the hummingbirds near the filter spout, and the still waterer for the insects on the farther side where the water wouldn't be moving (as much). I'm sure some trial and error will give good answers.
Graphic photo warning, for those who are squeamish of blood or injuries, the photo below is not for you. The kids took Tony down to the pool today (yes, not the other way around). It didn't last very long before #2 brought #5 back to the room with a big scrape on his foot. I guess he'd gone down a kiddie slide with #1 and his foot somehow got under her leg when they hit the bottom, scraping his foot against the bottom of the pool. Poor little guy. I put him in the tub and rinsed him off to get the chlorine off, then put some antiseptic on before drying him off and getting antibiotic cream and some band aids on him. He's such a trooper, he wanted to go back down to the pool! Unfortunately, I don't find public pools to be entirely sanitary and told him he'd have to wait for his skin to heal, or get some of the liquid bandage stuff on (which burns on application). He opted to stay in the room. Within about an hour he was back up and running like nothing had happened. He's pretty tough for just being three.