[Glyn]

ive got a tumbling tom tomatoe plant in a basket. When you say pinch out the side shoots What does this mean???

[Trillium]

You'll see the main stalk and from it will be a branch. In between the branch and stalk another stem (usually called a sucker) will start to grow and this is what you pinch out so it doesn't steal food from the main stems and turn into a jungle.

[jazzbyrd]

There is no need to pinch out side shoots on Tumbling Toms as it is a bush type tomato.
This link explains it very well.

http://www.tomatogrowing.co.uk/html/side_shoots___trusses.html

J

[mumofstig]

I don't think that you do this with the tumbling tomatoes as they're in a  hanging basket, so you need to leave them bushy...... it's only the types that grow up a pole that you pinch out  
beat me to it jazzy!