As for the phone, buttons can break. If it's out of warranty, you may be out of luck.
I have an iPAQ 5550 that I've had for years, love the thing. Bluetooth, wi-fi, big enough screen my aging eyes can see it, but mostly reflective so it's visible in sunlight. Touch-screen accuracy has been suffering lately, sometimes have to calibrate it 3 or 4 times a day, and the charger connection has to be angled just so or it won't actually charge. Can't make myself get rid of it, though, even though my smartphone has the same resolution screen (although smaller and washed out in daylight) more memory, faster processor, runs the same apps, and has a data connection. I still use the iPAQ as my PDA, not the phone.