Our current logo can be seen at http://foodtruckphilly.com/ -- we've been trying to change it to have a tie-in to the city of Philadelphia (like replacing the circle with a Liberty Bell, for example) but we just haven't been able to get it to work. We're open to all sorts of ideas, so don't feel limited to using the existing logo as a starting point.
This logo primarily will be used on our web site and mobile app, and will also be printed on to stickers which the food trucks can post in their windows, so people know to find their truck on our web site. We'll also make up a few t-shirts with the logo to wear when we (the web site owners) are at local food truck events.
There is a food truck association in Philadelphia; its web site is http://www.phillymfa.com/ -- we like their logo but don't want to imitate it. It's possible that a food truck may have some stickers on it to advertise web sites, and so we don't want their sticker and our sticker to look alike. Other logo stickers that appear on trucks include LevelUp and Square for payment processing -- so check those out too.
There are other food truck tracking web sites out there -- sites like Roaming Hunger http://roaminghunger.com/ for example. We don't like their logo, though -- it looks like shouting.
Our web site and app will be used by both locals and tourists, so we want a friendly logo that attracts the eye (when it's on a sticker on a truck) and is easily distinguished from other logos!
We will have more work in the future (such as a site redesign) so we'd love to find a great design partner.