Easy to get from OSM servers. People on wikicommons tend to tag them with **THIS SHOULD BE SVG! REPLACE WITH SVG!** templates though when they see vector'ish data.
Example SVG, showing the region of interest filling only a small portion of image
The mediawiki renderer doesn't seem to crop to the page edges. This means that it's pretty useless with osmarender SVGs, since it scales-down the image until absolutely everything in the SVG file will fit into the image.
