I just went on one of those Greek island tours where you visit a million different places on a cruise ship…but now I have no idea where I took each picture. We didn’t get an itinerary, and I don’t want to go through every picture and piece together which island I was on. Is there some kind of reverse image search that can help?
I don't know of any "reverse image search" but there could certainly be something like that. Some cameras these days have built-in GPS capability, that tags the location of each picture taken. However if you don't have that you'll probably just have to re-construct based on the information you have available such as which ports your ship was in each day. Once you have that information, you should be able to find pictures online.
We could be your reverse picture device. Post the pictures somewhere where we can access them then ask the question on this forum (Greece section). I'm sure some if your pictures will have some recognizable sight that we can recognize. Not all of them will show enough detail but if you have them in chronological sequence even if we recognize only some location it is possible for you to place the others taken immediately after or before.
You can try a Google reverse image search... upload the photo, and Google will search either for an exact duplicate or something as similar as possible. It probably won't work with all your photos, but it may with a few, especially if the geographic features in the background are particularly distinct.
Did the itinerary you chose name some of places you'd be visiting when you signed up for the tour? If your photos are in chronological order, you might be able to play a match game. I think Roberto has the best idea, though. I'm always amazed at what folks on this forum are able to accomplish.
I don’t know about image search, but if you took the photos with a smartphone or any camera with GPS like Ken suggested, you can use http://gpsonphoto.com to put the location/date underneath the image.
even if your camera didn't track GPS info, down in the metadata it kept track of the date and time you took each picture, so you could back into it that way.
Also tracks things like exposure info, flash usage, etc.
And speaking of geotagging photos, it's now recommended that you strip off all identifying metadata before putting photos up on the intergoogles.
"down in the metadata it kept track of the date and time you took each picture, so you could back into it that way."
This is true but is only accurate if your camera is set with the correct date and time. If it gets 'off' it can give you incorrect date/time info. Unfortunately I know this from personal experience.