I am holding in my hand the most useful guide-book I have ever seen in my entire life. Admittedly, at 2.67kg (nearly 6lb) it would take up more than 10 per cent of my airline luggage allowance, but I might consider throwing out my mosquito repellent and Swiss Army penknife rather than leave this monster behind. The World Travel Guide (Columbus Press, pounds 59.50), published annually for the travel trade, contains enough travel facts to get any traveller 10 times round the world and still not get lost.

Any guidebook that includes travel information on the USA, Benidorm, Antarctica and Iraq within its pages has my instant approval. And glancing through this masterpiece, the challenge I have now set myself is to find examples of the most obscure (ie interesting) travel information that has ever been published. I think I may have found some of it.

How about Pitcairn Island, just for example. That's a place I've always wanted to visit since watching Fletcher Christian burn his boats there in Mutiny on the Bounty. And lo and behold, here is all the essential information a traveller could need to know. Its location is described as "equidistant between New Zealand and Panama". Its population is 55, the majority religion is Seventh Day Adventist and the currency is the Pitcairn Dollar (Imagine a whole currency for 55 people. That must be a candidate for the champion of all obscure travel facts).

But while Pitcairn is a British Dependency, some other little-known islands in the South Pacific can boast fully fledged nationhood. One of these is Niue, an isolated island of one hundred square miles and a population of 2,000 (Language - Niuean; Religion - Ekelesai Niue). Niue's nearest consulate to the UK is in New Zealand but fortunately visas are not required for tourists anyway. Other deliciously obscure details concern plugs in Niue (which are of the standard three-pin type) and the Niue Post Office (which is open 8am to 3pm Monday to Friday).

Obscure islands are not confined to the South Pacific, of course. The eastern Caribbean packs a number of pleasingly unknown territories, such as the islands of the Netherlands Antilles. One of my favourites is the island of Saba, whose capital city has the improbable name of "The Bottom". With an area of just five square miles, I notice from the guide that the island is rather densely populated - it has a population of over 1,000. But in spite of the crowds, nightlife is still "generally quiet" during weekdays.

A vital additional note is included for those interested in doing business in Saba, namely that it is "very discourteous to be late" for appointments.

Along with the islands, huge empty spaces on maps such as the West African state of Mauritania are not neglected by the guide. This fascinatingly little-known country, normally only mentioned in the murky context of the slave-trade, in fact turns out to have an Honorary Consul in London as well as a Tourist Association (and Chinese restaurants) in the capital Nouakchott. Access to Mauritania from London, by the way, is remarkably straightforward, with connections on Air France via Paris twice weekly.

Equatorial Guinea has long been another one of my favourite obscure countries, tucked away just to the south of the great West African bulge. I now learn however that it has an embassy as near as Paris and furthermore, that it is a country of "luscious vegetation and much beautiful scenery".

Other gems of information included in the guide are that tips in Equatorial Guinean restaurants should amount to precisely10 per cent, while the Duty Free allowance when entering the country is 200 cigarettes and a litre of wine. There is just one prohibited item - Spanish newspapers. The background to this, sadly, is not explained.

Finally, I've always had a soft spot for Greenland, and for this destination, as for all others, the guide is a mine of useful information. To begin with, it turns out that flying time from London to Nuuk, via Copenhagen, is only five hours 30 minutes. And one of the least known but most fascinating facts I have so far been able to glean on Greenland is that sledge-dogs are only semi-tame. "This is just one reason why dog sledges should be given right of way at all times," states the guide.

With facts like that at your fingertips who really needs a Swiss Army penknife?