ATMs have become the preferred choice for money exchange when traveling and is the most common method now. The rates you get are better than money exchange booths, traveler's checks and banks. Read more on AMTs, fees and where they are.
You can change money at a convenient
"casa de cambio" (Money Exchange). These are money exchangers
that are open long hours and provide quick service.
dollars are widely accepted in resort areas, we recommend using pesos during your stay. Hotels can also exchange dollars, but these normally give you low
rates, use them as your last resort (pun not intended).
If you can't use an ATM you can get better rates
at the "casas de cambio", and the best rates at banks, but check around to make sure. You can also use their websites (use the bank link offered for offices and sites) to check what the current exchange rate is, you can also use the rate box on the top of the right column on this page. You can exchange money at banks between 9AM and 1PM
(even though they are open longer), this is because the Mexican Stock Market closes at that time. Expect a slightly
lower rate for travelers checks.
Many banks don't exchange dollars to pesos now, if you do go to one for exchange bring your passport along, there are limits to how much you can cash in, $300/day and $1500/month.
Normally there's no commission added on exchanges, but do ask beforehand to avoid any surprises. In any case they adjust rates to give them a commission anyway, banks never waste a chance to fleece us.
For the current exchange rate (reference only) use the following
Currency Conversion on Yahoo.com!