Be careful using your digital camera on the beach because sand gets on the zoom-lens and when it closes the sand can jam the zoom-lens making your camera inoperable. To avoid this make sure the zoom-lens is free of any debris before closing it.
Buy batteries and memory cards before you go to Mexico. Yes you can purchase these items almost anywhere in the Yucatan Peninsula and especially Cancun and the Mayan Riviera but you will find it is less expensive to buy these items at a discount store back home. All-inclusive resorts charge exorbitant prices for photo needs.
Use the highest quality setting when taking pictures. Simply carry more than one memory card with you in case you run out of space. Set your camera up before you even leave for vacation and do some experiments. Transfer the images to your computer or have them printed out at a photo-shop. Once you are comfortable with all settings, leave them there.
It is better to use the LCD Screen when taking pictures as this is exactly the picture you will get, which may differ from the image you see through the view finder. This of course uses more battery power so you should take lots of extra batteries with you.
Some Internet Cafes in Cancun and the Mayan Riviera have USB ports for you to dump your picture onto the computer and send them to a remote source.
There are Kodak and Fuji shops in Cancun that can burn CDs for you if you wish.
Some people recommend to always use the flash when taking pictures with a digital camera but you really have to get a feeling for this. Around noon on a cloudless day you may even have to use a filter to eliminate some of the ambient light. If your camera does not support filters then you can use a pair of clean sunglasses.
Check your camera to see if it has an exposure compensation feature. You may want to experiment with this if you are interested.
Taking your digital camera and/or memory cards through the detection devices at the airport will not harm your images in any way.
It is not recommended to take pictures of any customs area in the airport in Mexico or your departing airport [especially in the USA].