A small town (pop.~40,000) in south-east Cambodia and capital of the province with same name. It is a gateway to Bokor National Park
twice a day bus services from Phnom Penh to Kampot three companies: Hua Lin near Olympic Market, Capitol near Orasay Market and second rate Phnom Phen Sorya from the bus station on 217th street (near the central market). Buses leave early (around 7-7:30) or around midday. Expect to pay around US$6 for the bus (one way); you may get a free pick-up. Journey takes, depending on road conditions, approximately 4-5 hours.
Many guesthouses in Phnom Penh offer transportation directly from the guesthouse to Kampot. Convenient, although slightly more expensive. Expect to pay US$8 or more.
You can also get to Kampot from Sihanoukville by a shared taxi or minibus, with Sorya bus, or with G'day Mate's western-runvan service. Most taxis depart from the traffic pickup point next to the market. Two hour drive, US$3-5/person (although they start off asking $5 or more). The bus operators can help arrange a minibus with pickup at your guesthouse also.
Driving from Sihanoukville to Kampot on a 100cc rented Honda can be lots of fun but if road conditions are poor may take 3.5 hours or more. [edit]
Getting around Kampot is easy on foot, given the town's small size. Alternatively, hire a motorcycle (100cc Honda Wave, 125cc Honda Dream, or 250cc dirtbike) from near the central traffic circle or from just about amy guesthouse or tour shop. At the time of writing there are at least three different shops renting motorcycles. Going price starts from US$5/day for a 100cc bike (which is more than enough cubic centimetres).
It takes about 2 hours by moto from Kampot to the Ha Tien Border, the scenery is very beautiful. If you start early you can catch the 10:00h ferry to Phu Quoc island. The border procedure is hassle free.