If all you want is to put your snapshots on a blog then an inexpensive point and shoot camera will do the trick as the picture is quite small so I would suggest you stick with your iPhone and buy a lens for it. However, as you are already thinking bigger maybe you need more than this...cameras are like boats, IMO, you keep buying larger ones, and they are lots of fun. (My husband keeps buying better cameras so we have quite a selection.) So, if you have any thought that you might want to take good photographs, rather than tourist snapshots, I will suggest a different avenue. When I travel without a car, I take our inexpensive, essentially introductory camera, a Canon EOS T2i (they will have a new model now). I suggest this one because it can work like an automatic camera, but as you branch out, you can use a few manual settings or all of them to make your photographs even better. This camera with lens fits in my purse or daybag. It is not particularly heavy, but it is larger than a pocket camera. I choose a lens for travel considering strongly the weight of the lens as the weight of the lens is a consideration rather than choosing the perfect lens. I find it is not the camera base that is so heavy but some lenses (purely talking EOS camera here). If there is any chance you will want to print a decent size photograph or might actually enjoy photography, I recommend this DSLR. For example, I have taken my camera with the 50mm lens only. I have not been disappointed with the photographs...it does require you to compose your picture and move your body rather than your camera lens, but that works. This time I am considering the kit 15mm-70mm lens... I'd rather have the good camera base than multiple lens capabilities. So, to summarize, the weight of the camera is not necessarily the camera base, but rather the the choice of lens...stick to one (or two small ones, and carry one at a time). This camera will allow you to grow over time as maybe you'd like to print some cards or put a print on your wall someday, if so, get one to take photos that will look good beyond your computer.
I'll add that my husband also has one of those versatile, expensive, point and shoot cameras, which I keep picking up and putting down. It just doesn't do enough for me...and he hasn't really used it. It is a Nikon Coolpix P7800. Picking it up it is about the same weight as the EOS with the kit lens...and it is limiting in size of prints, etc. It would fit in a man's pocket...not any I own. Of course, it would easily fit in a purse.
There is no right answer, just many, many considerations. Wray
PS: And I'll add, the best camera is the one you will have with you.