Wikipedia has a version of the site that is optimized for mobile devices, which was officially launched in June 2007 as a wap site, but now is located at http://mobile.wikipedia.org/ There have been alternative, unofficial mobile Wikipedia sites for some time, including Wapedia.mobi which has been around since 2004.
The official mobile version of Wikipedia brings up a simple, quick-loading page, which features a search box front and center. Below the search box, there is link to a settings page and an “About Wikipedia” page.
The settings allow you to choose a language. Currently, there are 14 languages available on the mobile site, including Arabic, Austro-Bavarian, Czech, Germany, Greek, Spanish, French, Hungarian, Ripuarian, Low German, Dutch, Polish, Portuguese, and Serbian. Though, popular languages like Japanese, Italian and Russian are not yet included.
The other setting option is “Spoken Wikipedia”, though once you go that page, you see it’s “Not available”. Not totally sure what the spoken feature will entail, but there are some Wikipedia articles with audio versions, recorded by Wikipedians.
http://en.wikipedia.org/wiki/Wikipedia:Spoken_articles
The search feature on Mobile Wikipedia works the similarly to the “Go” button on the regular Wikipedia site. If there is a likely match, Mobile Wikipedia will take you directly to the article (e.g. “Barack Obama”). If there are multiple possibilities for your search term, you may be taken to a disambiguation page (e.g. “Georgia”) or a list of results. Also, only article pages are included in the search. Thus, pages useful to Wikipedia editors, such as the administrators noticeboard, are not available.
One issue mobile version is that the disambiguation links you see at the top of some articles when looking at the regular version of Wikipedia, do not appear on the mobile version. So, if you searched “Washington”, for the city, it brings up the page for Washington State, with no disambiguation link at the top.
Another usability issue with the mobile site is the searching. On the regular Wikipedia site, when you start to type something in the search box, a list of possibilities pops up and helps fill in the rest of the search term. This is not available on the mobile version, so you need to type the entire search term.
Once you are on an article page, you see just the lead section of the article (above the table of contents) or possibly more, but still a small portion of the article. Loading just this portion, makes the page loading much faster, and there are no images. The Barack Obama article, for example, is broken into 30 sections. Then there are links to “Continue…” to the next section of the article, and a “Contents” link to see the table of contents and skip to another section of the article. Other differences include no templates or infoboxes, no tabs (e.g. history, talk page, …) and no editing.
Though there is no history tab, there is a link on each page to a “Copyrights’ page, which makes available the GFDL license (a requirement for Wikipedia content), a “Source” link (takes you to the same article on the regular Wikipedia site), and a “History” link, which provides attribution to the Wikipedia editors who authored the article (also a requirement of GFDL).
The mobile site is powered using Hawhaw (http://www.hawhaw.de/), which is an open source project.
Despite some of the shortcomings, Mobile Wikipedia is a quick and useful way to access Wikipedia content.