From time to time there have been a number of questions on mixing strobes with daylight. I was just out in South Padre a week ago and captured some good candids to illustrate the process.
Here's the set up we used:
It's a Dynalite Uni 400jr with a Jackrabbit battery hung using a Bogen Superclamp on a piece of electrical conduit.
This is Jerry Brown using the unit to shoot Amanda:
And here's the result with my camera:
The unit is VERY handy - it also serves as a closet for the model!
Here's a with and without. We were setting up on top of a hill and I snapped this one without the strobe:
And this one a couple of minutes later with the strobe: