Rofl who manually drags!? i use GIMP, which allows you to set the size of the pic before you make it, and resize inserted images to specified pixels :3
When you use the resize tool and click on the image, a box pops up and shows the height and width measurements. Just type in 100 in both boxes (Or whatever sizes you want) and then click OK/Apply/whatever it is and shebang, you have a resized image… 😛
I don’t think many sites have a resize pointer. It’d be hard to do, you’d have to specify what x and y of the picture to start at, and that changes depending on..anyways, yea, just use Paint. :3