actually i have had that problem with turning on on every PDA but my Axim (axim had the power button on the frount face). i actually thought about this the other day and decided to make it a sliding switch that went
OFF => ON => Hold
onto the psion, if i was going to get one i wouldnt pull it apart for the pocket pengunie. i guess i am a PDA collector, personally i would rather get my own on EBAY.
that said i do have a casiopea A-11A without RAM (it had ethier 4MB or 8MB of ram. and i wish i had the pinout so i could make a new ram chip as the ram chip had the OS image on it as well (it had flash chips). keyboard wasent the greatest but it was the perfect form factor, large screen (wide but nice, unfortunattly B/W) and an alright keyboard. it did however have pcmcia and run off AA batteries. it looks like the psion with a crappier keyboard
i have also been thinking of the sub laptop size/UMPC size one and how to make it a more powerful device compared to the PDA version. mainly to do with video cards and how to make it a dual processor machine (stand alone, not plugging in the PDA)
this is mainly due to me looking at the cerrunt state of the hardware and assesing what i want out of a mobile platform (not what is avalible). the PDA is nice to whip out quickly but somtimes you want the form factor of a laptop but still retain the portability. this has alot to do in my mind with location aware programs and HMD (of which i am doing a bit of side R&D. ill split this into another fourm post as i think its worth discussing.
i think the biggest hang up with the project at the moment is the design tool and my lack of ethier windows or openGL and wine under linux (i sware those nvidia drivers are nothing but hell, not to mention that any kernel greater than 2.6.15 wont boot on my PC so no precompiled modules). but fear not work will progress, i dont think ill meat the december deadline i gave myself but i am also waiting to see if any new tech comes along while working on the project