Sure, the Treo 800w was a blip on the Windows Mobile radar and has now even disappeared from Sprint's Web site. But eight months after its release, one cool feature has now been discovered:  the 800w can act as a USB host.

So what does that all mean?  In short, with a cheap $8 adapter cable (like those found here on eBay) you can connect up all sorts of USB devices that don't require separate drivers to run.  Such devices include external hard disk drives, USB flash drives, USB headphones/mics, and for bnsguy, a USB ultrasound probe!

What makes this unique is that at the moment, very few WM devices can act as a USB host (if you happen to know any, drop us a line) and to be honest, it is a really cool feature that we would like to see on future devices.

After the jump, we'll post a few shots of what this setup looks like on the 800w and some various USB devices that can run on it!

Basically how this works is very simple: plug in your USB device to the special USB host cable, plug into 800w and then turn on. That's it, really. So long as it doesn't require external drivers and does not draw too much power, it should work. So some digital cameras with USB modes should work (although my Nikon D90 lacks that feature, pity) as well as various other USB gadgets. Things like HDD and thumb drives simply show up as "Hard Disk" under Resco Explorer and act just like storage cards.

First up is a biggy: the Western Digital My Book 1TB external HDD.

This big guy requires an external power supply to obviously power the HDD and when plugged in it will actually show up on the 800w and be fully accessible. One note: if you try to use the "properties" option say in Resco Explorer, it will crash and sometimes it will take a few seconds to read a whole directory. But c'mon ... 1 TB of data!

Next is the most convenient: USB thumb drives

What is nicer than being able to take your thumb drive, connect up to your phone and just transfer or access files on-the-go?  With quick read times and the ability to shuffle files between your microSD card and the thumb drive, you can easily add GBs of storage to your device.

Finally, how about a USB stereo gaming headset with microphone?

This one even we were surprised about.  Turns you you can plug this headset in and have all your audio routed through the stereo headset and even use the on board microphone. Uses? How about those long Skype calls. Seems to work quite well over that sevice.

Things we're working on to test: USB to 3.5mm stereo headset adapters.  Ironically, one of the Achilles heels of the 800w is a severe lack of 3rd party headphone adapters. One solution which might work is to use one of these adapters, which converts sound output to 3.5mm as well as enhances the audio. 

We'll keep you posted on that one.

Thanks to bsnguy and haus!