I already have a netbook. Iphone is definitely a nogo. 100% touch screen dedicated devices blows your manhood to a grinding halt from teeth (touch screen is great, but having devices that only function through a touch screen is the computer industry going overboard with a new interface technology).
Don't forget my 170$ limitation here either. Iphones out of there along with a new netbook, but the new netbook does allow you to put whatever software you want on there (iphone on the other hand is largely a closed device). And, **** the dsi, it's browser sucks, and the dsi in actuality doesn't have enough memory for surfing the web making it's web surfing ability blowing your manhood to a grinding halt from teeth. You can get homebrew for the dsi, but getting homebrew for it sucks just as much as getting homebrew for the psp.
You guys need to check out some of these open pieces of hardware and consider how much more awesome they are for portable emulation gaming since they are specifically designed for homebrew. Right now the hype in china and korea is portable open hardware (stuff that's meant to be hacked and for people to develop their own programs for).
Dingoo a320. I'm really considering buying one of these. The idea is too cool. It's 82$ and does 7 hours of gameplay. Not to mention the device is open. The dingoo community ports emulators to this thing all the time. And before that, dingoo digital (chinese company) that made this put a good deal of games on this thing with tons of emulators for you to use the first moment you turn it on. The community also makes it's own apps, bug fixes, and improvements for the device. The community even got together and made their own distro of linux for it, they support the standard firmware as well as linux for it also. Great collaboration on this awesome piece of hardware.
The
gp2x wiz is the essentially the same exact thing as the dingoo; the gp2x wiz was built for portable emulator gaming purposes as the dingoo a320, is just as open as the dingoo a320, has the same kind of community making apps, porting emulators/apps, ironing out bugs, making software improvements, and even their own distribution of linux they made for the console. The gp2x wiz is korean and is manufactured by gamepark holdings. This one also has a touch screen and stylus, but largely what the gp2x wiz was built for, how it's used, and the games it plays; you can already imagine how useless a feature touch screen is for the gp2x wiz. A lot of people who buy and don't read the manual and just know how to use the console...it might be a while before they discover the useless touch screen by accident.

Both consoles have big communities surrounding each portable emulator console, but the dingoo a320 is getting more attention because of the price, better controls, and better battery life. Other than that, the actual differences between the consoles is not much.
DINGOO A320 82$ GP2X WIZ 164$
4gb on board flash 1gb on board flash
400mhz ARM processor 533mhz ARM processor
32mb RAM 64mb RAM
miniSD storage expansion slot SD card storage expansion slot
If you want a follow up on both of these,
here's a video of both consoles being reviewed at the same time by one of the dudes working on the pandora project.
What's happening in reality is that people like the dingoo a320 better because hardware-wise it's not that much different than the gp2x wiz, dingoo a320 and gp2x wiz both do their jobs about the same, dingo a320 has better controls, dingoo a320 and gp2x wiz are both built pretty sturdy, dingoo a320 is also half the price of the gp2x wiz. Both great awesome ass consoles designed for homebrew, both also fast enough for a special install of linux to run a web browser and surf the net or use IM, sadly neither has any sort of wireless, and especially no ethernet port.
Keep the suggestions coming though.