One of the most common fears of travellers is being taken for a "ride" by taxi drivers.  It's an easy scam as travellers don't know current rates or local taxi regulations.  But with WorldTaxiMeter, you need not worry.  It calculates the taxi fares for your trip in some of the top destinations of the world.  There's also a mobile version for the techie traveller in your group!
Another job for you before you head off on your trip. Good luck!