Experiences...too numerous to list. BUT, yes, invitation to be mugged or worse may be true. I was always tempted to use my iPod and the in-ear sound-isolating headphones because everything is SO LOUD here, and the classmates are so chatty AND LOUD...you know what i am talking about if you have ever been to a shopping mall in the RP. But since my courier-bag got stolen last year while I was seeing a patient in the out-patient department along with my iPod, I have not enjoyed the luxury...
My cell phone, during ALL of medical school ONLY got stolen ONCE (pick-pocket on the LRT 1, on my 30th day in Manila...) and YES, we tend to keep our cell phones "on us" at all times...you'll see how much people TEXT here...My advice is get a "clip-on the belt" case and keep it on the anterior area (of your waist) where you'll notice if someone tries to take it...
(BTW, one-time stolen wasn't that bad...I had a classmate who in two years either 'lost' or had a cell phone stolen about SEVEN times!).
The other thing related to SAFETY ISSUES....you know that "iTower" new building that has a hot-link posted in this thread? A (male) UST student (I think from Rehab Sci, but definitely not Med) was SHOT and KILLED on the sidewalk across from 'iTower' (UST fence-side of P. Noval) in 2007 when he was robbed and he refused to give up his backpack. May that unfortunate victim rest-in-peace, he is not forgotten...even though the 'shrine' and candles haven't been at the site for a while now...SO, just be aware!