SVGSlice is a simple tool which generates chopped up images from Inkscape SVG drawings. To figure out where to cut, SVGSlice can use Inkscape's built in guides (for simpler, grid-like cuts), or it can use a specially named "slices" layer that contains rectangles that mark areas to slice. Demo files showing both approaches are included.
Instant Picture Creator is a wrapper to produce images on demand for Web sites. It has filter management, and it's possible to add new filters. It can cache filtered images, works independently (no backend is needed), and is easy to integrate with existing Web sites. It includes two basic filters for resizing images and manipulating colour palettes. Currently it supports PNG, GIF, and JPEG.