Embassies
Singapore
Singapore nationals may register online with the Embassy at (https://eregister.mfa.gov...).
Internet
Sunny Internet
178 st, opp foreign correspondents' club, also sisowath quay, next to the riverstreet restaurant. provides a faster service at us$1/hr and is popular with tourists and expats.
Wireless and wired connections for laptops are available at a number of outlets. Most five star hotels provide high-speed broadband access, but at a premium. A number of cafés along Sisowath Quay including the Foreign Correspondents' Club expensive, Fresco Café under the FCC, also expensive, K-West Café at the Amanjaya Hotel, the Jungle Bar and Grill, and Phnom Penh Café near Paragon Hotel and Metro Cafe free.
Galaxy Web
Street 63, near sihanouk boulevard. excellent service, popular with westerners.
telephone
Cheap SIM cards for GSM phones are available on almost any major street. A vendor should have an activated test card to be used to make sure your phone will operate on that network. Calls between mobile networks can be be spotty and Skype calls from abroad to mobiles in Cambodia are sometimes dropped, so be prepared to redial frequently.It's now easier than ever to buy a sim card in Phnom Penh, just have your passport and expect to pay no more than US$2. There are plenty of phone stalls around central market. Mobitel has the best coverage around the whole of Cambodia and seems to have cheaper calls. Be warned when sending and receiving international SMSs and calls as they only have about a 50% success rate of being received.
post
The main, impressive French colonial style post office is located at the intersection of Street 13 and 102, roughly between Wat Phnum and the Riverside, also selling postcards.Another branch is more downtown, at the intersection of Sihanouk and Monivong Boulevard.Both offices offer full range of postal services, including PO boxes for affordable prices, and are open 7 days a week.
Postage for international postcards is 3,000 riel as of March 2012 - very nice picture stamps are available, philatelists: ask for mix and match options.Letters and especially parcels to Phnom Penh's post office frequently go missing, or are not made available to recipients for up to one year.
noise
Phnom Penh is a noisy city. Unrestrained blasting of car horns and a city-wide construction boom put strains on the sanity of the visiting foreigner. There is barely a location in the city that is not within earshot of sledgehammers and power saws. Stay away if you are noise-sensitive - or at the least bring earplugs, earmuffs, an iPod, or whatever it takes.