Hi Jesse! I went to Italy for two weeks by myself last year as an end of college present, and I have a little system..
First off - I only give my camera to people I can out run (which is often times older travelers). At times I had to be persistent, because people would see me taking photos of myself and be pretty adamant that they help out. (Another safe bet is when someone asks YOU to take their picture, afterwards, switch and have them take yours). I signed up for a few tours on my trip (Collossem in Rome, Vatican, a gondola tour in Venice..) and felt very safe asking the other tour members to take my photo. Another tip, if we were in a confined area (on a boat, on top of the Duomo, ect), I would have people take my photo. As long as you are willing to give chase, I’m pretty sure you could get your camera back in those situations.
Before you go on your trip, practice taking photos of yourself (so you can get good)! If you can afford it, get a camera with a wide-angle lense. (I have the Canon SD800). The wide angle lens make you look a bit farther away and does a great job of getting more of the background in. I took pictures of myself in front of everything famous. And I got stared and laughed at a lot.. but not in a mean way. More of a, “What is this girl doing?” kind of way. Just be confident, you’ll be fine.
I actually really liked how my photos turned out. My friends laughs and says it’s the same picture of me 500 times with a different background. But whatever =)
Have a great time!