No, sorry, Dragonchilde was correct.
Ten minutes three times a day is just as effective as 30 minutes once.
However, it would be wise to warm up for each first!
If every workout has a 5 minute warmup, then in a 30 minute work out you get 25 mins 'work', and in three 10 minute workouts you get 15 mins 'work'. Perhaps that is the difference Chris was meaning.
But absolutely, breaking up your workouts is far better than doing nothing at all because you don't have the time to do 30 minutes at once! :) www.sparkpeople.com/resource/fitness_artic