Physiological tomato leaf roll is what it is called. Linked one article on it below but Google will pull up many more info sites on the issue too.

It is fairly common when plants are grown in containers since it is quite difficult to provide the consistent soil moisture levels needed to prevent it.

Dave.

Here is a link that might be useful: Phys. Tomato Leaf Roll

Yeah, the plants are stressing a bit, but IMO it falls into the "normal" range of growth and shouldn't be a problem in the future as far as tomato production. The plants should grow fine. Any chance you could add more mix to the container and fill it up?

This post was edited by edweather on Tue, Jun 24, 14 at 19:10

What is the variety ?
I was growing a Black Krim last year. Its leaves were curled (tubular) like that all summer. I had 3 other varieties in the same bed doing just fine. STRESS ?! from what condition ?
Here is a BK