Johannes Beus
Even though the worldwide networking of the Internet has many advantages, it is often the case that a users wishes to find a site that is located in a confined regional perimeter. So, while that hotel in New York might be extremely pretty, it would be conceivably unsuitable as accommodation for the next Abakus Pubcon. For a while now, this market is being plowed by different national and international searchengines. Here is a short overview of the contenders
Google

The searchenginegiant is integrating their local search into their mapservice “Google Maps”. The data for this seems to come from researched yellow-pages, even though Google extends these informations with data from the homepage of the company if a URL is present in the yellow-pages. In cooperation with partners, Google superimposes ratings and comments over the results. The researched places are then displayed on the map that is known from Google Maps. Like so often at Google, the local search might not be anything special but it is a solid implementation with a comfortable interface, unmatched speed and a good database.
Advantages: speed, usability, maps
Disadvantages: results are constraint to the yellow-pages thus the currentness is lacking
Yahoo

Yahoo's local search – sill marked as beta – is being operated in cooperation with the yellow-pages “DasÖrtliche” who are providing the data. Similar to Google, the yellow-pages serve as the data basis; however, it seems that Yahoo does not search through the homepages of the companies and is therefore only offering limited functionality. With a little bad faith, you could call Yahoo's service searchable yellow-pages. The maps are from map24 – which have, for years been known, for their extremely slow loading maps, if they load at all.
Advantages: thanks to the cooperation with “DasÖrtliche” they have an extremely good database, neatly arranged
Disadvantages: no real websearch, slow mapserver, seems a little lackadaisical, yellow-pages based
Suchen.de

Suchen.de is a cooperation of different German businesses under the direction of the I-Info GmbH which has its own search-solution ever since October 2006. Unlike their American competitors, suchen.de is sticking more strongly to informations that are extracted from the Internet by a robot. This means that the robot, called Gonzo, will visit websites and will then try to extract informations like addresses, contact-informations or even business hours. After a comparison with existing databases, the gained data will then be fitted with geodata and can then be searched for. This is an interesting approach which will surely win out in the future seeing that it is not constrained by the manual maintenance of yellow-pages – the relevancy of searchresults however is not always apparent at the moment. The returned sites are, as known from the other searches, shown on a map.
Advantages: crawls the Internet for informations, therefore it should in principle be more current and comprehensive than solutions based on yellow-pages, neat user interface
Disadvantages: relevancy is not always given
Web.de

Web.de is also trying its hand at a local search. Just as Google and Yahoo, they are using researched data as their basis – Web.de is relying on Schrober-data in this case. The search, which is also marked beta, will show the results – as is sufficiently known – on a map overview. Sadly this is where Web.de stops, which means that, like Yahoo, they are only offering good, searchable yellow-pages. If you are looking for current data fresh from the Internet, you will be searching in vain in this local search.
Advantages: clarity, solid database
Disadvantages: based on yellow-pages, only the most rudimentary options were implemented – no special features