Edgar hit on the problem, in a roundabout way. Frogs just head for somewhere cool and damp/wet at certain times of day.
My horde sit merrily on the pondweed (garden pond) with just their noses sticking out of the water all day. They occasionally have a quick "griddip" with each other, but on the wholw they are a lazy bunch of buggers.
When that sun goes down behind next door's hedge mind you, they are out of the pond in no time, guarding my plants by scoffing almost their own weight in slugs and snails all night.
What they need is a "wet" garden to laze around in. It doesn't have to be a pond, is easy to do, and brings no end of wildlife into a garden. Great "discovery" part of the garden for kids, as well. These things can be built so they are child safe, and I've even seen them with low, natural style fencing, to keep squawking diaper wearers well away.
Then the frogs will probably ignore the swimming pool altogether.
Here are some ideas....it may even bring in a bit of business, GW.
http://www.bbc.co.uk/nature/animals/wildbritain/gardenwildlife/myspace/content.shtml?18
http://forums.gardenweb.com/forums/bog/nph-ind.cgi?n=90