Placemat - Pretty nice placeholder images.
DevToys - A collection of converters, formaters, encoders, generators and other tools for your Windows desktop.
PlaceKitten - Dead-easy placeholder images. Of kittens.
Lipsum - One of the oldest and fastest 'lorem ipsum' (random text) generators.
placeholder.pics - Lightest way to include placeholder images in your design
Lipsum.pro - The superfast Lorem Ipsum text generator