I have an O2 XDA Orbit, with Windows Mobile 6 installed. I think there's faster, sleeker versions of the same thing now (the Orbit is a rebadged HTC P3300), but it's quite nice, albeit slow.
It has a touchscreen, GPS, GPRS, camera, WiFi etc, and the battery life is reasonable.
It's nowhere near as slick as the iPhone - Windows Mobile feels a bit like going back to Windows 95 or 98, but it does have the advantage that it's not all locked up so there's a lot of software out there you can put on it. And of course it has GPS.
I've not actually tried reading yacf on it yet, but the built-in internet explorer for it seems okay for most websites, and you can also download Opera for it.
If you're prepared to put up with Windows Mobile, there's quite a lot of options out there depending on the features you want that you may not get on the iPhone (e.g. GPS, flick-out keyboards, 3G etc). The user experience however is not as smooth, although some vendors have added their own iPhone-like interfaces on top of Windows Mobile.