Air

Pochentong Airport is about 7 km from downtown. The trip into town takes about 20 minutes. The official taxi rate is US$7. Motorbike "taxis" aka motodup can be hired for as little as US$1-$2. Departure tax is US$10 (domestic) and US$20 (international) and must be paid in dollars.

Water

Most travelers arriving from Siem Riep take the daily speedboat. The boat departs 13 km south of Siem Reap daily at 7am and costs roughly US$25.

Land

There are currently two legal overland routes to Phnom Penh: Hat Lek/Koh Kong on the Thai border near Trat, and Bavet/Moc Bai on the Vietnamese border on the main highway to Saigon.

The journey to Saigon takes about 10-11 hours, depending on how much time you're held up at the border. Most travelers opt to hire a shared taxi or minivan through a travel agent or hotel for between US$6-$20 per person. Daily vans also leave from Phnom Penh's Capitol Guesthouse and Narin Guesthouse. (From Saigon daily trips are organized by Sinh Cafe on Pham Ngu Lao Street.)

If entering Cambodia at Koh Kong you'll need to spend the night in order to catch the next morning's ferry to Sihanoukville which departs at 8 am. From Sihanoukville you can catch a bus to Phnom Penh.