Bus Travel
An option to flying is to take the bus. Fares seem cheap enough, booking from any travel agent in Bangkok it is easy to get a bus ticket one way for 900THB, this can be up graded at the Cambodian border in order to complete the journey by taxi. The bus leaves Bangkok at 7.30 AM and if you are lucky the driver might know Bangkok well enough to find the highway,
When you reach the border they play a cute little scam. They stop at a shop where you are told you have to fill out the visa forms. They then try to get you to pay 1300THB for your visa. Do not be taken in by this. Politely refuse saying that you will pay at the border. Doing so will save you about 700THB.