Here are the swimming holes between our city home and our ranch that we visited this summer:
Krause Springs
Colorado Bend
Our swimming hole on the Colorado RIver
Devil's swimming hole at Inks Lake
Blue Hole, Wimberly
Pedernales Falls
Llano river
I'll rate them but, they are all good. We just like the places where you can spend a day or more better.
1) Llano river (free) near Kingsland, Pedernales ($5/adult, kids free) & Colorado near Colorado Bend State Park (free for us) - Lots to do, can spend an entire day or more. The Frio would be up here also but, we haven't made it there this summer.
2) Colorado Bend ($5/adult, kids free) - Gorman Falls is worth the hike and the swimming holes are nice but, small.
3) Krause ($5/adult, $4/kids) - Cold water in the spring fed pool, nice trees, a good hour or two stop.
4) Blue Hole ($7/adult, $3/kids) - not cold but, refreshing, beautiful water a good half hour stop. A good stop on the way to Fredericksburg from Austin. However, Pedernales Falls is also on the way if you are looking for a longer stop.
5) Devil's swimming hole, Inks Lake ($5/adult, kids free) - nice if you are camping there but, probably not worth a stop.
All my "good" pictures had kids in them. All from July/August 2010.

Llano river swimming hole with packsaddle mountain in the background, still fairly unknown outside of the locals.

Pedernales Falls State Park

Colorado River swimming hole, South side of island North of Bend and a few miles South of Salt Creek.

Gorman Falls (You can't swim here but, there is a shallow pool between the park boundary and the Colorado river where you can enjoy the cool water.

The shallow pool at Gorman Falls between the park and the river. I don't have pictures of the swimming holes on the South side of the park.

Krause Springs

Krause Springs pool (as cold as it looks)

Blue Hole, Wimberly

Devil's Swimming Hole, Inks Lake. Kids like to jump off that cliff and the bolder ones go off the top of that big boulder. It's not much as far as cliff jumping but, that is one of the main activities.
[This message has been edited by HECUBUS (edited 8/9/2010 11:29a).]