Wikitravel's scope is ambitious -- especially for destinations -- from the most obvious visitor centers to such remote spots as Antarctica, Adak, and -- my favorite "behind the beyond" spot -- the Kerguelen Islands in the South Indian Ocean. Organization is hierarchical, with detailed guidebook-style information on each major region -- Africa, Asia, Central America, the Caribbean, Europe, Middle East, North America, Oceania and South America -- then detailed information on major political regions within each region, more details on individual countries, details on sub-regions within larger countries, on states or districts within sub-regions, on important individual cities and locations, and on many individual attractions such as Yosemite Park, Grand Canyon and Disney World. But you have to learn how to dig through hierarchical databases, because the site's search system doesn't work very well: It returns "no results" from a search for the Aleutian Islands, for example, but the Alaska page does have a link to an Aleutian page.
The "Travel topics" sections slices the information a different way, with separate hierarchical listings about the nuts and bolts of travel, starting with overall topics, such as basic differences between areas, reasons to travel, different classes of accommodations, travel documents, transportation, staying in contact, packing, travel health, safety, money and exchange, an all-purpose "cope" section, working abroad, travel activities and events; plus individual sections for the major world regions; all of these main topic headings leads to further detailed sections.
Overall, I find much of the information to be reasonably accurate and useful: The sections on overseas use of plastic, for example, and on overseas telephone options seem to be good. Sadly, however, the information on airlines is a mess, with lots of inaccuracies:
-- The section on "discount airlines" is especially irksome. In the first place, there is no such thing as a "discount" airline: Each line sells seats at its own list prices, and real discounting -- by third parties -- is an entirely different matter. Beyond that basic conceptual problem, however, you encounter some outright errors: the assertion that Laker was the first low-fare airline, for example, and that Southwest invented the low-cost model in the United States are both inaccurate.
-- The section on consolidators repeats the hoary legend -- untrue -- that consolidators "buy tickets in bulk" from airlines. This one is really hard to eradicate.
-- The section on "air courier" seems quite outdated, in that it implies that courier travel is still an option. As far as I can tell, it really isn't anymore, at least to/from the United States: None of the courier agents I've examined in the past are still in business.
Also, some of the listings for my hometown, Ashland, Ore., are outdated -- but you find that problem with most other destination sources, as well.
Despite a few shortcomings, I'd list Wikitravel as a useful resource -- not your only resource, but a good one. And it eagerly invites you to edit and improve its presentations, based on either your experience or prior knowledge. All you have to do is register and then get to it.
(Send e-mail to Ed Perkins at eperkins(at)mind.net. Perkins' new book for small business and independent professionals, "Business Travel When It's Your Money," is now available through http://www.mybusinesstravel.com or http://www.amazon.com)