Not sure how I could've missed it earlier but PalmAddict's Andrew Davis wrote a very complete review on the
OQO model 01+, a device that doesn't exactly fit the description of a handheld nor that of a notebook device. The review, which is
composed of three parts, concludes:
All in all, in my opinion the OQO rocks! I love it. I now have an OQO in one pocket and my Treo 650 in the other. I have the utmost in portability and have internet access, my documents, and programs, etc with me all the time. I couldn't be happier... well, at least not til they come out with a better version of each. 
And that said, there are rumors of a 2nd generation device due out from OQO sometime this year. If it happens, I'll definitely be getting one and I'll donate my current OQO to a worthy Palm Addict reader... so keep watching PA on a daily basis!