Mith said:
Does anyone know how well laptops, PDAs and computers stand up to vibration?
Also how to they handle damp, like as in a covered place, but with outside air around them?
PDA's...no real problem with vibration due to no moving parts.
Laptops...actually able to withstand surprisingly high shock loads. I believe the harddrives are rated somewhere in the range of 300G. A bigger problem might be harmonics. If the vibration has a harmonic freq, it may cause problems with the read/write heads in the drive.
Regular computers are pretty similar to laptops as far as the hard drives goes, however the case is not constructed anywhere near as durable.
Now your big problem....high relative humidity can be a problem, and can lead to over heating. If you are talking about condensed moisture, you are pretty much out of luck. A PDA sounds like the safest option for the limited set of requirements you listed.
What is the application you are looking at?