Firstly, belated birthday greetings.
Secondly, some of the suggestions on the thread are not so bad; offering to mow lawns, wash cars, clean swimming pools, for neighbours, and do other jobs that no-one really wants to do in order to make a bit of money. As you are only 13, I'm not sure that legally you would be old enough for a part time position in a place like McDonalds.
Thirdly, LIGHTNING suggested a raincheck for your birthday (which I hadn't realised was today), which is a good idea; how about a bit of a raincheck for Christmas, too, and ask any other relatives - uncles, aunts, grandparents, siblings, to contribute - in a raincheck sort of way - to a future iTouch. Adults like the idea of contributing to a present that hints at the idea of 'deferred gratification'. It also means that contributions can be made by installment, rather than all at once.
Best of luck with it.
Cheers