City.Mobi
Usability: 
city.mobi/ (xhtml-mp)
Guides to hundreds of cites around the world. The site is offered in eight languages and covers Africa, Asia, Europe, the Americas and Oceania. That's clearly a lot of information here although usability could be better.
The guides are essentially lists of hotels, restaurants, shops, entertainment venues and travel and transport providers. The listings consist of the address, a click to call phone number and in the case of hotels a star rating. All good basic information but it could be organized better. For example, for San Francisco City.mobi lists over 500 hotels, five to a page, 125 pages total. The listings are city wide and there is no way to sort them or search for a particular hotel or location You can filter by star rating but that's it.
Another usability problem is that there are active links to unfinished parts of the site. An example is an "Events" link that leads to a "Coming Soon" page. This is classic garden pathing which wastes mobile user's time and money. If there's no content, the link should be removed or disabled.
