Native App versus Web App
I have a PC.
I have an iPad.
Must I also purchase a MAC to be able to develop apps for the IPad?
There are lots of advantages to developing a "native" App for the iPad, which gives you access to hardware features.
However, if you don't have a Mac, consider developing a web App. The browser on the iPad can run web Apps. If you know HTML and JavaScript, you can produce a web App that can run on the iPad, an iPhone, an Android and even my personal favourite, the Palm Prē.
A web App can be developed on your computer of choice, including your PC.
For more information:
Chapter 9. "Mobile Web Apps Versus Native Applications" in Mobile Design and Development by Brian Fling (O'Reilly / Safari).
"Developing for the iPhone OS: App Store vs. Web Apps" (if you're coding for the iPhone or iPad, you have to choose) by Ryan Faas in ComputerWorld.
Among other things, a web App can be made available on your terms, quickly, without submitting to Apple's App Store requirements.
NOTE: I'm a Newbie on this Forum, so I apparently can't post links. Try googling "web app versus native app". Let me know if you would like links to the above.