How DO they get the jelly in the donut?

As dumb as it is, everyone has asked themselves this question at least ONCE in their lifetime. Humans, as a general rule of common psychology, have a certain nature. An impulse, if you will. This is called curiosity, and everyone has it. (And I swear to God, if you try to be a smart-ass tell me that you don't, I will know that you are lying and I will personally find your home address and knock on your door just so you will open it and I will SLAP YOU.)

Ahem. Anyway, consulting one of my best friends- The Webster's Comprehensive Dictionary published in1977- I found that the definition of "curiosity" had a much deeper meaning than just "killing the cat".

cu.ri.o.s.i.ty (kyoor'oe.os'e.te)- n. pl. .ties 1 Desire for knowledge of something. 2 Inquisitive interest in the private affairs of others. 3 An interesting or strange quality. 4 Any object adapted to excite interest or inquiry. 5 Obs. Fastidiousness; nicety. [ < style="font-style: italic;">curiositas, -tatis CURIOUS]

Pay close attention to definition No.1:

cu.ri.o.s.i.ty (kyoor'oe.os'e.te)- n. pl. .ties 1 Desire for knowledge of something. 2 Inquisitive interest in the private affairs of others. 3 An interesting or strange quality. 4 Any object adapted to excite interest or inquiry. 5 Obs. Fastidiousness; nicety. [ < style="font-style: italic;">curiositas, -tatis CURIOUS]

Curiosity is a big part of life in any human being. Which proposes my original question as to how they get the jelly in the donut.

And so, curious as I am, I did a little internet research (Not being one to trust internet information in situations when I'm not doing homework, I would have used my encyclopedia, but I disappointingly found out today that the word "donut" isn't in it. Sighhh...)

Here's what I found after typing "Jelly Donut" in the Google searchbox:

A link to a very racy website that I wish I had never clicked.
A link to a jelly doughnut cupcake recipe that I am glad I did click.
A link to a YouTube video of the Food Network's "How to make a Jelly Donut"
And multiple photos of jelly donuts.

So how do they do it?

When I typed "How do they get the jelly in the donut", I got a few Yahoo! Answers and Answers.com links that popped up.

It's injected using an icing bag, or similar type injector.

I don't know about you, but I am greatly disappointed. I would have been more interested in the answer had it been an interesting one, like that they plant magical jelly seeds in the donut and when its baking the seed grows in the heat and bursts, leaving jelly for those who want it.

Oh well. I guess I'll turn my attention to how they get the custard in a donut. :)

What's your theory?