Technologically, Beijing is a city at a crossroads. It is the capital of the world's largest mobile phone and Internet user markets, and its universities, especially Tsinghua University, produce some of the world's top technology minds. At the same time, Beijing cannot compare to its Asian neighbors, namely Tokyo, Seoul and Hong Kong for Internet and telecom services, such as 3G (third-generation telephony). Its Internet access is censored and far slower than in those cities: China Netcom's fastest consumer ADSL (Asynchronous Digital Subscriber Line) is sold at 2M bps, but often clocks in below 1M bps. While China wins gold for the size of its technology markets, it is in many cases an also-ran in terms of the quality of technology implemented.
The basics: Electricity in China is 220v, 50 cycles. Power in Beijing is consistent, but surge protection of some type is advised. Plugs are two, flat vertical pins, like in North America, and three-pin plugs, with one flat vertical pin, and two slanted pins, like in the U.K. Adapters (for the plugs that are not voltage converters) and power sticks are readily available at department and large grocery stores.
The biggest issue the visitor will face will be language. Although Chinese schoolchildren study English for years, the emphasis is on reading and writing, not speaking and listening. Therefore, the average taxi driver and restaurant employee speak no functional English. For taxis it is almost essential to have your destination written down in Chinese to show to the driver. You can also overcome the language barrier with the Immersion Guides' Mandarin Phrasebook, which provides not only the English phrase and its Chinese equivalent in characters, but also the Pinyin romanization, in case you want to try to say it as well.
Getting connected/mobile phones and landlines: China's current mobile phone technology is 2G (second-generation telephony) GSM (Global Standard for Mobile communication). Most dual-band, tri-band and quad-band handsets will be able to connect here, provided that you have the ability to roam overseas with your service provider, and your service provider has a roaming deal with either China Mobile or China Unicom. Check with your provider before leaving home. Blackberry service is supported in China, including T-Mobile's U.S. service, but again, confirm this prior to departing for the games.