Khlong Thoey - river taxi
The cheapest way to get around when compared to BTS/MRT but at your own risk and it stinks!
It is also a bit tricky to know the exact price to get from one point to the other.
Oh also, nowadays, it's probably the easiest way to get around with all those red shirt around because BTS are now randomly closed, depends on the red shirts mood.
BTS line : hi red shirt people, how do you do today?
red shirts : fine, we are happy with the heat and sitting down all day
BTS line : oh excellent, we don't need to close down the BTS today