Using handheld computers in ecological field work

[Ingar Pareliussen]

I wonder if there was anyone that had used Psion 3c, USR pilot or
similar computers in ecological field work. 
This summer I am going to perform a plant abundance mesurements and 
need a reliable palmtop that can run a simple spreadsheet program,
(one colomn with latin name and 18 columns behind for ecological data 
and about 100 sutch entries pr. day), easy to use, low power consumption
and weather hardy.