Software for travellers
Tourism is a multi-billion dollar industry and it's hardly a surprise that many large and small software companies are offering various tools to help the traveller on the road. A lot of this software can be safely ignored; however, a few are truly invaluable and deserve some mention.
Metro is a small application originally developed for the Palm Pilot platform. It stores the route plans of subway and/or bus services of various cities around the world. It allows you to easily find the best connection between two places using the public transportation network of your current city. It will display instructions on what lines to take, where to change, and an estimate of how long the trip will take. It does not store schedules. The current version (April 2004) covers over 250 cities from Australia to Wales.
The author of these lines tested it with various cities (Paris, for example). Metro does a very good job at what it was designed to do. It's highly recommended for anyone with a supported PDA who travels into a city with more than two subway lines.
Solun is an application giving information about stars and other celestial bodies.