My free 1 month visa is expiring on September 5th, is there a cheap why for me to renew my 1 month stay? Can I take a bus to laos or cambodia or something? 

About a week before 5th September go to the Imm' office near you and for 1900 baht you can get another 30 days. Those 30 days will start at the end of your present 30.

You seem to be referring to visa exempt stay in Thailand, not wishing to be pedantic but you don't renew it, you ask for it to be extended, you should follow the advice given by the previous poster.

 

I'll move you post to the correct forum.

The above answers are the most easy way to obtain another 30 days. Just to add to that info, yes you can go to a border, exit and reenter with another visa exempt stamp 30 day stay.