Remember, the one sure fire way to avoid the "revenge" is to arrive in PV, go directly to La Farmacia, purchase some Cipro OTC, and start taking it...keep in mind that the dosage for the intestinal tract is about half that of the UT.
Fondest memory: Not getting the revenge because I took Cipro.
Be sure and put your tourist card and passport along with airline tickets in a safe place, preferably in the safety deposit box in your hotel. You do not need these papers with you at all times and it is a big hassle if you lose them!
You will see many beggars on the street. I swear, some of these ladies with babies have a different one every couple of months. I would not recommend letting them pull at your heartstrings as its pretty much a scan.