Web User being able to update the drop down values

[eluser]rdtech[/eluser]
I have a question with regards to drop down fields. I want to be able to give users the ability to add to values to the dropdown fields if the value is not present. For example, I have a form that has a drop down with a list of fruits. If a user stumbles on to my site and sees that I'm missing a fruit, he/she can add to the list. Is this possible with Expression engine? Are there any plugins or modules that would give this feature?

I've looked at freeform but I dont think they offer this. If programming is the only viable solution, can someone point me in the right direction.

Paul