iPhone Development on Hackintosh
Yes, it's totally possible. I developed my first app on a Dell running the iATKOS OSX patch.
Whether it's worth it or not really comes down to how difficult it is to get a hackintosh install (Kalyway / iATKOS) running on your PC. With some PCs it's trivial and everything works. For others it's a nightmare and your networking/audio/graphics will never work completely. If you need to run a patched kernel (e.g. you don't have an Intel Core 2 Duo chipset) things become really awkward.
Your best bet is to take a note of the hardware in your PC and do some research on the various OSX86 forums.
Assuming you get everything working the only future concern is software updates. iPhone SDKs generally require the very latest OSX update (e.g. 10.5.6), but installing updates on hackintoshes with patched kernels is a nightmare.
If you enjoy tinkering with this type of thing and are comfortable partitioning your HDD and playing with boot flags then I'd say go for it. If not, consider picking up a used Mac-Mini on eBay/craigslist or something. If you find out that iPhone development really isn't for you then you can resell it lose practically nothing.
Yes, you can, but save yourself some time and pain.
Pick up a Mac mini or an iMac.
It's possible. But you are restricted to the choice of hardware for the hackintosh. Even if you get it right, no one can guarantee everything will work (sound, lan, etc.). If you can run the OS, you can run xcode with the SDK. But I don't think you'll be 100% satisfied with the end result.
As I see it if you want to run os x it's better to invest in a mac mini than in hardware for a hackintosh. Asuming you'll be buying all the components for the hackintosh.
I was in this dilemma recently, and decided to go with a real Mac rather than a Hackintosh after hearing the stories of my friend (who is doing it specifically for iPhone development). He was able to get iPhone development working, but his hackintosh is always having one issue or another; the most recent one was a constant boot cycling, wherein the machine would immediately reboot after loading the OS.
Look on the bright side: Apple products are popular and easy to sell. If you get one and sell it before the next generation comes out you can get most of your money back - money that would have been spent anyways on a new hard drive (to quarantine your hackintosh, heh) or OSX (assuming you meant to get the software in at least a remotely legal fashion).
Yes, you can. I have. But is it worth it?
If you are doing it for fun it's worth it.
If you are doing it for a real, useable Mac it's not worth it.
Now you will have a billion guys come down on me for saying that because some guys have built some truly impressive rigs but they are missing the point of a Mac. Macs just work well and are a pleasure to use while PC's just get stuff done and you probably secretly hate it.
I did it just for fun but I ended up spending more on a Hackintosh than I would have if I just bought a Mac Mini. Of course my computer is 4x as fast but it's just not the same as a real Mac. On Mac's everything just works... it's really nice. But on my Hackintosh nothing works without direct intervention on my part... not very nice.
I always planned on using that computer for windows development anyway so it wasn't a waste but otherwise it would have been a HUGE waste.