Seems to me there could be a way to do a rough texture like the material on a tennis ball using Inkscape.

Can you provide some approximation which gives some realism, perhaps a particle effect of some kind? Anything which would be give some roughness/fuzziness to the traditional glass/metal sphere.

I think filters are the tool for that, but I'm not sure if you can find those in the official version (0.46). You can try downloading a development version (if you're on windows don't - dev version on windows is unstable at the moment).

Search for inkscape filters on openclipart.org, maybe you can find exact texture you're looking for.

Thanks, I found a likely candidate which worked out well.

Im pretty sure heathenX did a screencast based on chrisdesign they have a sports school tutorial section and one covers tennis balls they achieved the texture using a couple of interesting methods all in vector, may be worth a quick look on their pages.