pyGTK-based image viewer/editor with very large collection of Public Domain clipart. Downloadable from ibiblio, browsable on homepage. WP Clipart is a collection of public domain images specifically tailored for use in word processors and inkjet printers. All are non-transparent PNG files of quality clipart, illustrations and photographs. You can view all clips online at wpclipart.com or download the whole collection hosted by ibiblio.
Viewer is packaged for both Windows(in binary format) and Linux (source -- see the readme file for dependencies). The viewer is NOT necessary use/edit the images, but extremely handy. Aside from filter, rotation and resizing, the editor can save to a clipboard to paste into apps such as OpenOffice, Word, AbiWord, GIMP and others.