A few of my tomatoes have developed this light brown pattern (see images). I can only think a disease? Can I treat this?
I can't really see the tomato well in your pic but it might be Tobacco Mosaic Virus. Does the patten on your fruit resemble this pic?
I think it is late blight; we had a big problem with late blight in 2009. For information about late blight, see the streaming video recording (see link) of a webinar about late blight that took place in December.
Here is a link that might be useful: eOrganic Late Blight webinar