Nokia N810 4.13" Tablet

The N810 not easy to categorize.  In some ways it is like a smartphone, in other ways like a PDA, but really it is sui generis, a pocket media gadget and wi-fi communication tool.

It does not contain a cellphone.  To connect to the internet you must have wi-fi or bluetooth tetering.

In some areas it truly excels.  It is the best pocketable web browser I have ever seen.  Even the most obnoxious script-heavy and Flash-based sites (Facebook, YouTube, et al.) render surprisingly well.  The built-in IMAP email and chat clients are quite good. While most portable video players are very fincky about the codecs they accept (and therefore rely on your computer to transcode everything), the N810 actually has a decent chance of playing a downloaded video straight off.  The VOIP and videophone cabablity is superb: SIP, skype, and Gizmo5 are all supported (though no video on Skype...apparently that requires too much processing horsepower for any portable device).  You can use the built-in mic-speaker, stereo earbuds, a standard corded cellphone headset, or a bluetooth headset.

Its design has Nokia's characteristic utilitarian bent.  Not sleek like an iPhone (which in my view sacrifices usefulness for looks) , but tidy enough, and yes it does have real keyboard, replaceable battery, SD card slot, and usb connector.  It uses a stylus type of touch screen, again reflecting utilitarian concerns--accuracy, compatibility with traditional GUI design--over multi-touch slickness.  It can't pinch to zoom; you use a +/- button on the top.

You don't have to know any Linux to use it, but if you are proficient in Linux...well, you know who you are, and you know the power of Linux.  You can get a shell prompt, program it in Python, run an SSH server, and so on.  Root login is possible.  Non-GUI apps are available with apt-get.  And you can do Linux stunts, like (to take a recent example) use an SSH proxy to bail out the iPhone-wielding guy sitting next to you whose Facebook access is blocked by the Great Firewall of China.  Its GUI is not an X implementation, so you can't just download .deb or compile tarballs (for GUI apps).  GUI apps have to be ported, but there is quite a bit of stuff in the repository.

Even if you don't know a whiff of Linux, you still benefit from the many programs ported over.  I use an HP-42 calulator emulator (for complex numbers), GPE organizer suite (the built-in organizer isn't very good, more on that later), and Pidgin. I find it easier to use the Pidgin's facebook chat module than to keep the facebook's obnoxious webpage up continuously.  This is also the only portable device I have found (besides Palm OS) that can do non-toylike actual useful work in Chinese for someone who knows Chinese only as a second language.

A couple shortcomings are surprising.  It is not very good as an organizer.  The native contact function is rather primitive; it does not, for example, support street addresses, nor separate work/home numbers.  The open-source GPE organizer has been ported and it works well, though it is much easier it sync through GMail than directly to your computer.  If you are accustomed to the snappiness and logical layout of Palm OS, you are best served by the extra-cost PalmOS emulator.  The camera is really intended just for video calls.  You can't even use it as a camera without downloading extra software.  In my view, a good camera is useful as a camera, but a poor camera is a net liability because some places don't permit cameras.

In sum, this is not the easiest to use, nor the slickest device out there, but it is exceptionally powerful--almost a netbook replacement--once you learn to use it.  If you are looking for a device that is useful, and don't want to be chained to a ruinously expensive cellphone contract, and wi-fi is what you expect to use most of the time, and have modest PDA/organizer needs, then this is a gadget to fall in love with.