I have a triple entry visa issued by the Thai Consulate in Canada.
I have used my first entry, then got a 30 day extension. At the end of this month I need to get my visa renewed.
Can I get my visa renewed for my next 60 days at any border crossing like Burma or Laos or Cambodia?

They way I understand the process, is that since I already have my visa approved for triple entry it's just as simple as leaving the country and re-entering to get a new stamp, is that correct?

That is correct, you can use any border for that.

But keep the validity of the visa itself in mind, all entries must be made before that date!.

Leave Thailand , enter different country (you may have to buy an "on arrival visa") , leave the different country and enter Thailand using your second entry. Make sure you enter your visa number on the Entry card .

Edited June 14, 201313 yr by Sceptict11

You can use any border crossing but must enter the other country before returning to Thailand.

You will not be renewing your visa you will be using the 2nd entry of your visa to get a new 60 day permit to stay.

Yes, but know the limitations of a double entry or triple entry visa.

First, such visas have an expiration date.

All entries on such visa must be used before that expiration date.

Any unused entries are canceled after that expiration date.

Second, you need to exit Thailand and return (can be done immediately) to activate another entry. That means getting an exit stamp on leaving Thailand. Without that exit stamp they won't activate your re-entry.

Thirdly, you will need to enter the other country. and that other country wants you to get a visa to enter.

But it's possible.

It's called a "border run" where you travel to a Thai border, exit Thailand, then enter another country, then immediately turn around, exit that other country, and re-enter Thailand.

It's a common thing.

Thanks everyone for being so helpful!