I got my orange persian Titus as a lost pet/shelter kitten at 4 months, and he has always loved to be cradled belly up-he follows me around and loudly demands that I do that as soon as I get home from work-but unlike my dog, or the Midget, he will not come when called...
And I have a relative that can train them so well, that they will use the toilet and flush afterwards (no kidding) I have never attempted that, and didn't believe it myself until they demonstrated the cat doing it for me.