A very simple way of putting your logo and phone number out to the public while having some fun at the same time, would be to have a kite sign.
The kite would have your logo and phone number on it so it, would have to custom made. You may be able to stencil the letters onto a large kite. You can do this just like you did the lawn signs earlier by filling in the stencil lines. If you were to have a kite contest, you could have your phone number in large letters with one number per kite.
The kites could then be flown in formation so that your name and phone number would be spelled out. It is highly likely that you could get a picture of this in the local paper as publicity stunt.
You may decide to have several of your single kites with your complete name and phone number on them for sale at a reduced rate. Kids will want to have the larger kite with your logo on it to fly rather than just a plain kite. You could create some more publicity by sponsoring a kite flying contest for a local boys or girls club. Have the kites as part of the prizes. Being as you are the sponsor you can have all the contestants wearing your T-Shirts.
This is similar to how the large radio stations or soft drink companies stage their contests. Let the kids keep the T-Shirts after the contest so that everyone will get something from the event. It doesn't hurt that your logo is on all those shirts so they'll remember for years to come that sponsored the contest. So will their parents, your target market! "Go fly a kite" will have a new profitable motive for you now!