The bussystem in Cambodia has improved a lot, there are busses going in every direction from Phnom Penh. Rides are between $2 and $6. Busses go to Battambang, Sihanoukville (Kompong Som), Kompong Cham, Kompong Chhnang, Kratie, Siem Reap and a lot more smaller destinations.
The main busstation is at the Central Market, but there are many other companies scattered all over Phnom Penh.
Most busses stop at their favorite places for food, at these places the busdriver gets a free meal. Good opportunities to use the bathroom, but sometimes these stops just take too long.
It costs US6 for 'new' bus from siem reap to phnom penh. However, it is possible to get US4 for slightly 'old' bus.
The features for the new and old buses are the same except may be the air-con is not very cold for the old type.
There is a world of difference between the domestic arrival terminal and the international departure terminal. This is a picture from the latter. In this terminal there is a small cafe and a nice shop selling Cambodian crafts.
There is a daily boat from Siem Reap (Angkor Temples) through the Tonle Sap lake. It takes 5 hours and costs 22 USD. It is a small boat, so if you don't arrive on time, you will do the trip on the roof (which is very pleasant BTW). If U do so, be careful with the sun, is really really very strong here...
You are supposed to put your luggage at the rear part, but as I arrived late, I put it on front, and it was much more convenient when leaving the boat, as I didn't have to wait the long queue (see pic) to pick up my rucksack.
Tickets at any guesthouse or travel agency.
The best way to travel between Phnom Penh and Siem Reap (for Angkor) is to use the speedboats that leave from the quay south of the Japanese Friendship Bridge.
See my Angkor Wat transportation tips for my experience on this boat.
My 12th grade English teacher, Mrs. Lowry, taught Joseph Conrad's Heart of Darkness partially by showing in class the movie in inspired: Apocalypse Now. That film, my personal favorite, documents the journey of Captain Willard and his PT boat crew up the river into Cambodia. My teacher, a 75-year-old woman at the time, would always quote Willard's line: "Don't get off the boat... unless you're going all the way." She would point at one of us in her class and in her old school Virginia accent, remark, "I remember a boy who used to sit just where you're sitting, Mr. Hatcher. He's dead now. Wrapped around a tree. Yessir. Dead and gone. So don't get off the boat, Mr. Hatcher, unless you're going ALL the WAY."
I mention this because now, you too can replicate Willard's boat trip. SaigonTourist offers a boat trip up the Mekong River from the Vietnamese Delta to Phnom Penh. The Vietnamese portion is by standard riverboat, with shaded awnings and comfortable chairs for reading and watching the scenery go by. Once you reach the border, you disembark and walk into Cambodia.
After clearing customs, you step on a speedboat and go blasting up the river toward the capital. The ride is insane, bumpy and exhilrating. Your heart flies into your throat as you try desperately to keep your belongings in the boat. Fortunately, the Viet Cong and Khmer Rouge won't launch rockets at you and you will likely arrive on dry land safe and sound.
BANGKOK / THAILAND:
Thai Airways and Bangkok Airways both have daily flights.
KUALA LUMPUR / MALAYSIA:
There are daily flights from Kuala Lumpur Sepang with Malaysia Airlines.
SAIGON/HO CHI MINH CITY / VIETNAM:
Vietnam Airlines operates this route. There are up to two daily connections.
VIETIANE / LAOS:
Lao Aviation flies twice weekly to Vientiane and sometimes with a stop in Pakse. A oneway ticket is up to 195USD.
Silk Air are operating this route but I don't think that it is daily.
A new airline called Mekong Air just started operations in March 2002 and flies from PNH to BKK, KUL, SIN, HKG and other destinations.
By Air : There are direct flights to Phnom Penh from most neighbouring Asian countries. There are also 6 or 7 flights per day from Phnom Penh to Siem Reap which takes 40 mins and its free seating. Be prepared for a bag search at Siem Reap.
By Road : You can also travel by road from Vietnam.
If you are in Ho Chi Minh City, Vietnam (Saigon) and you want to visit Phnom Penh you can just take the morning bus for about $10.00 USD. The bus is cheap and easy and it is the gateway to see a new country from Vietnam. The drive is quite nice also. If you want to go by boat to Phnom Penh from Ho Chi Minh City this is possible too through the canals of the Mekong Delta. There is a company that does this (contact the Kim Cafe or Shin Cafe Travel Agents) but it is more espencive than the bus and takes about the same amount of time (only a few hours 6 maybe, i forget).
To go from Phnom Penh to Ho Chi Minh you can take a share taxi mini van for only about $7USD. The walkabout hotel can hire the van for you or tell you where to get the share van.
Taxis charge a flat rate of USD 7 (7 EUR)between the airport and the city. If you are around the city you might get it cheaper. A lot of guesthouse offer transport to the airport for around 5 USD (5 EUR)
You will arrive at Pochentong Airport which is 3 KM Southwest of the City. entry requires a passport, and VISA on Arrival for $20. You need a passport picture. After leaving the airport you can take a taxi, or Moto into the city.
Transport around the city is usualy done by moto. Usualy cost is a dollar or 2. You negotiate before you go. You can also hire Moto's with driver for $6 or 8 a day. Be sure and bargin, and never pay the driver in advance. Moto can take you to places like the Killing fields, and airport.
You can rent Moto's, but driving takes nerves of steel, and requires large deposits.
A hint. get several thousand Reil, and offer the driver about the equivelent of .50 US cents, around 2500 Reil.
If you are leaving the city you can either take the bus near the Central Market. There are 3 bus companies that will take you to wherever you need to go.
Fast Boat will take you to Siam Reap for $25 and take about 5 hours. This route is better than over the road which will be bumpy and takes about 8 hours. Bus will probably be cheaper though.
You can get long distance Taxi's on MV Charles De Gualle Blvd & Monoving, and the Central Market. Renting a taxi to Sihanoukville May cost about $20, if you want to just buy a seat about $3 and you will be crammed with other passengers. A taxi to Siam Reap is about $80. Cheaper to fly than a taxi. The cost of a flight is around $55. Check at your guesthouse, they might have cheaper arraingements.
There are several companies offering boat rides between Phnom Penh and Siem Reap. Fast Malaysian managed boats take 4-5 hours in a small, uncomfortable boat for USD 20 to 25 and 6 hours in a large, comfortable boat (compared to previously 12 or up to 24 hours.) Prices are USD 12 to 20. The Cambodian government has assigned soldiers to guard these boats. The soldiers use the time on the boat to take a snooze, but you can make interesting contacts if you hand out cigarettes to them. If you are lucky they will ask you to join them in the evening in Siem Reap when they tour the bars and shoot the moon! Other reports state that somtimes the soldiers are shooting on the boats.
There are also slow boats. They should take 2 days during the wet season, and 4 days during the dry. It is possible to get a ride in a cargo boat for as little as USD 7.
These boats are quite dangerous. There have been many accidents, boats capsizing, etc.
The ferry port in Phnom Penh is just north of the Cambodian-Japanese Friendship Bridge, a couple of kms from town center.