Microsoft has a wonderful tool to cure this problem. Its called Image Resizer. Once installed, you can simply right click on any image and it will resize it for you, greatly reducing the photo kb/mb size, and keeping a good quality for posting. Thats what I always use, to reduce my 2-3 MB photos down to KB for posting, emailing, etc..
You can also highlight multiple photos, right click and resize them all at one time. It keeps your original image, and creates you new images called xxxxx.jpg_resized