Modern Vespa

does anyone know where to get one

Depends on the size you want and what you are using it for. Since you asked on here, I am going to assume that you want something for your MP3. You can pick up small (maybe 1 foot by 4 inch) battery charging panel that ends in a 12 volt socket plug (cig. lighter plug) at Radio Shack, Fry's Electronics, or probably at a variety of auto stores.

Here is one on Amazon http://www.amazon.com/Sunforce-50012-Solar-Battery-Maintainer/dp/B0006JO0KG/ref=sr_1_7?ie=UTF8&s=automotive&qid=1217431852&sr=8-7

I picked up one of these for $10 at a Radio Shack a couple of years ago. I also have a setup of 3) 25 Watt panels and 273 amp/hours worth of batteries as part of my "camping gear".