As promised, here's my kinda dell mini 9 hackintosh howto and my experiences with it.
Pretty simply, I followed the instructions here:
MyDellMini - How-To: Install Mac OS X - DellEFI Method
It is a LOT easier if you have the retail disc for 10.5.6. Apparently if you have anything prior to that you have to do a lot of patching. You need 2 flash drives, one for the disk image, and one to boot off of. The disk image usb drive needs to be large (I used 8GB) and the boot one needs to be 1GB I think.
In addition to the guide there, there is a really active forum there, and I think the community is one of the biggest assets of the dell mini 9 hackintosh setup.
Other than some oddness right after I did the initial install (where I basically had to reboot one more time than the guide said), the whole thing took about 4 hours, which isn't so bad for a format and fresh OS install.
So if I didn't say it before, the hardware is awesome. It's just this tiny light machine that I feel like I can take anywhere pretty comfortably. I really can't envision a trip where I can't find a way to squeeze this into my bag or backpack.
Once I had macosx on there, the machine ran great. The write speed of the SSD drive is a little slow sometimes, and a lot of the forum denizens recommend upgrading it, but I'm actually fine with it as is.
I was surprised that the webcam worked pretty much right after the install. Same with the sound, wi-fi, and bluetooth. The main developer occasionally posts patches on the site which improve battery life or something else, but for the most part, I just leave it as is.
I was surprised that core OS functions like the software update work seamlessly.
The two big downsides of the device of course stem from the very small form factor.
The first is the low resolution. The screen only does 1280x600, and as apple doesn't officially support any display under 800 px, there are some prefpanes and screens that just can't fit on the screen. Similarly, some web sites just look wrong at the resolution given, namely, embedded video in a google reader frame will often not fit.
The keyboard is the second big downside, and that's just cause they had to remove so much to fit it in. First of all the keys are very small, so like any notebook, it's just not as comfortable as typing on a real keyboard, and I make a lot of mistakes when I try to type fast. Second, they have gone crazy optimizing and removing keys, to a ridiculous extent. The quote button is next to the spacebar, making it unusable. There is no backtick key or tilde key, but rather a Fn-combo for those characters. Same thing for the square and squigly brackets. I would hate to attempt to write code on this. But of course that's not what it's for. For e-mail, browsing the web, and IM, it's pretty great. Except that quote thing. I really don't know what they were thinking there.
Anyway, for a cheap hobby hackintosh, you can't beat the value, form factor, hardware compatibility, and ease of a Dell Mini 9. I highly recommend it.