[rubinjames]

Could agree more with sampeng about the river boats , a great way to travel especily if you want a cheap scenic tour of bangkok and have a camera. An addition note there are three boats , two are express boats both of which carry a coloured flag; red or yellow indicating that they are express boats and the no flag boat that stops at all piers. Please note that the river boats stops at sunset they dont travel after dark.

[Sampeng]

The boat in the photo is the tourist boat witch I dont like because you have to listen to the same commentary on the Tanoy every time and its 5 baht extra. For the first time visitor its good cos the guide will point out what you are looking at on the riverbank.
At most piers there is also a small boat that will take you straight across to the other side. You can also hire a longtail boat if sitting on a piece of wood and having a diesel engine roaring behind your head is your idea of fun.