I ran across a pond photo today on Birds & Blooms website, and immediately thought: "I like that! That could work in my yard!"
It has a small, shallow-ish pool at the top end, then water falls over a spillway to the larger, deeper pool below. The small pool would allow birds to bathe safely, while the larger pool would be deep enough for small fish.
My yard is almost perfectly level, so I'll probably be building a small hummock at the top, to provide the option of a spillway. And my dimensions will be either 10x20 or 12x18, I think.
I'm still researching plants and ideas, as well as city regulations, but am hoping to create it next spring.