We were driving around East Europe this summer, and used my Psion Series 5 for maintaining our trip journal. I made a simple script for converting Psion Word documents into web pages. The results can be seen at http://reissut.nemein.net/
We also had the idea to use the Psion's CompactFlash slot for uploading images from my Digital Ixus to the net, but as we were using GSM connectivity this proved to be too expensive -- each image took about 13 minutes of upload time. However, we at least were able to prove that the concept worked by uploading some four images.
Other way to handle this was to connect the Psion to a computer in an Internet Cafe, but unfortunately most of them didn't allow this.
Next year I think we will bring along a travel modem for the Psion and sign up to a globally roaming ISP to make the image uploads more sensible. I would be very interested to hear about experiences with such a setup in developing countries.
Next year we're also planning to use the Psion for uploading GPS track logs for automatically generating route maps, but this will require more thought and effort.
Ein Schwein, das nicht fliegt, ist nur ein gewöhnliches Schwein