Make them smaller!
Your camera or phone is set to take big pictures. most of them are set to do that by default. That is why the files sizes are 1 - 2MB each. Images this big are good for posters and other big needs but way too big for most any monitors that people would have. Even 10% of that is pretty big for a monitor. There are two choices here:
1) Change your camera/phone to take smaller pictures.
2) Once you take the pictures use your camera/phone to resize it to a smaller size.
Note that smaller here does not really equal worse resolution as far as most things are concerned. It just means instead of being 24"x30" it is 8"x12".