Local Harvest Gardening

Our tomato plants are getting too tall, is it a good idea to prune off the top?
If so, where should I make the pruning cut?
They are growing against a south facing wall and have been staked.
They are Beefstake, Juilet and Cherry tomatoes.

It's August 1.

It's a good time to top the beef tomatoes. Any new flowers probably won't ripen into fruit this late in the year. Top above fruit you believe still has a chance to ripen before September 15.

Cherry tomatoes could wait until mid August before topping.

For indoor tomatoes that are protected from dew and fall rains, we could wait another 15 - 30 days before topping.