I need to go to Thai Immigration and I live in Min Buri. Even though I reside in Changwat Bangkok can I apply for, say, a tourist visa extension in Chachoengsao?

You have to apply at the immirgaiton office for the area where you reside.

For a tourist visa it is accepted that you go to any immigration office, but they might ask for some proof you are staying in their area. Like a hotel bill.

Thanks, Mario. I caught your reply just before I left this morning. But I chose not to take your advice. The repulsive thought of driving from Min Buri cross town to immigration in Bangkok in the AM rush hour and the mob that I have to compete with there compared with an easy, relaxing, 45 minute, scenic country drive to a comparatively sleepy immigration office was contrast enough that it forced me to follow my gut feeling and take my chances in Chachoengsao. My instincts served me well.

Not only did they, upon questioning, agree to service me without the slightest blink they actually bumped me up while I was waiting. Number 27 was on board and I had number 39. The entire process, from first taking my ticket through walking out the door with visa extension in hand consumed all of 45 minutes. Needless to say I was a mighty happy and grateful camper. The girl that handled my extension was a bit blush when I heartily thanked her with a "Khorp khun mak khrap" and gave her my most best and proper wai.

Anyway, just wanted to report back on my experience but would otherwise not recommend my option to anyone else. File under, "Don't try this at home, kids."