Although cookies, like ideas, may be half baked, you never can tell when someone might find them tasty. Fossil ruminations may initiate a landslide of sequential inspirations, to thoroughly mix metaphors.

I agree with sand. You'll never know if an idea will be useful later on.

I would like to see two things that I feel would really improve this site.
1) That an option would be provided to me to "Hide" all of the Ideas I have already voted upon.
2) That Ideas are promoted in each category based on a formuala of 3 factors. How often it was viewed by different people, an interest rating, and a feasibility rating. So that way the ideas with broad appeal and high feasibility that have been sufficiently viewed rise to the tops of the categories. Something like:
List Priority = (Interest_AVG * w1 + Feasibility_AVG * w2 + #Viewed/#Membership * w3)
Where w is a factor assigned based upon experience. Then sort the list based on the Priority.

You said you deleted one of your old ideas, how did you do that? I don't see any options, nor do I see a method to email other members. There must be an area in WhyNot I have yet to explore.

Instead of deleting them, how about moving them to a new category for "stale" ideas, just in case someone wants to browse through them?

I like the idea of an option to hide (and unhide) the ideas ones already voted on.