Well...have just come back from the gym and this is what the personal trainer said:
Stomach toning:
Any exercise will tone your stomach if you engage your "core" muscles.
If you stand up and put your hands on the lower part of where your ribs are - just above your waist - that is where your core stomach muscles are. Visualise pulling in those muscles - you won't really feel anything change on the outside, but you should feel a tightening (from the inside) just above your waist.
Now, you need to practise engaging your core muscles a bit but when you've mastered it apparently every exercise you do will really benefit your stomach - toning wise.
He said that very small, focused, sit ups were good. Lie on your back. Don't strain your back and keep your hands on your ears to support your head. Pull up gently until you feel the tension in your stomach - but not your neck - and engage your core muscles and move up and down - but only by about a couple of inches or so. I have been given the task of 4 sets of 10 reps - i.e. pulling up and down 10 times, short break and then repeat (4 times).
He also said hula hooping was good - Scotsmist was right!!
And also don't forget the sides of your waist as well. Stand up straight - legs shoulder width apart. Put one hand on your hip. Engage the core muscles and reach over your head with the other hand til you feel the tension. Again - do small focused movements up and down and then swap to the other side. Do about the same amout of sets/reps. All this sould only take about 10 mins per day but the results are supposed to be great.
Hope this helps - if it doesn't make sense then let me know.
LLx