1. Stay calm
If you approach them in a jumpy persistent mood they will probably find you are nagging, which will put them in a bad mood. Be calm, if they say no, don't get angry! Just leave.
2. Have your reasons!
You will need a good reason to want the newest iPad or a brand new touch screen iPod, not just because all your friends at school have one. Make a list of reasons they might say no, and then write some REASONABLE answers for them.
3. Be Patient!
I remember that time I really wanted a video camera to make a video diary for my baby brother. I am STILL waiting for one, and have been asking for a year, but I have a sneaky feeling I'll be getting one for Christmas! :) You may need to wait a while for your birthday or Christmas. To show you REALLY want one, make a birthday wishlist or Christmas list and put the apple product at the top, in bold, with lots of arrows pointing to it :D
4.Compromise
Maybe say that you will pay half if they pay half? If you dont want the full price you can easily buy a much cheaper one on Amazon or eBay and it will still work just as well!
Thats all I can really tell you without writing down the exact same thing as How to Persuade you Parents to Let You Get Your Ears Pierced! Enjoy!
Love,