I loved Ardell's answer: "Easy. You sell it in the future when "future value" becomes present value."
Beyond that, though, there are some techniques for doing that. Consider a lease-option, or even a straight option. In simplest terms, an option allows you to lock in a price today, and gives you the right to purchase at that price at some point in the future.
Now, I'll acknowledge that in a declining market it's difficult to persuade someone to pay more than a property is currently worth. Still, to take an extreme example: Consider a community in which houses were selling for $200,000 in 2000, and $400,000 at the peak in July 2006. They're now selling for $275,000. Fair enough?
Suppose the owner of one of those now-valued $275,000 houses said: "I'll give you an option to buy this house in 7 years for $305,000. The option will cost $1,000 and, if you buy, I'll credit the option fee to your purchase price." The seller wants a 10% premium--10% above the current $275,000. And I can lock it in at $302,500 for up to 7 years for $1,000. Honestly, I don't know for sure what the house will be worth in 7 years. But that strikes me as a pretty good deal. I'm betting $1,000 that a house will go up in value by 10% in 7 years. Not everyone would go for it, and that's fine. But some people would.
Now, as you adjust the numbers to be a bit more aggressive--say a purchase price of $330,000 in 5 years--a 20% gain in a shorter time frame--you'd get fewer takers. But that's still a reasonable gamble, for many people.
You can, if you want, couple that option to buy with a lease. Rent the property at fair market value. Or rent it at slightly above fair market value, with the excess being credited toward the purchase price. Now, I know some Realtors here really don't like lease-options. The argument is that if you want to rent, rent. If you want to buy, buy. For most people, that's good advice. But lease-options do make sense for some people who'd like to lock in a price, clean up their credit, and save for a downpayment.
Meanwhile, the question here was from the perspective of an owner: How does he sell for a little over the appraisal, as he put it. And Adelle had it right: Sell it in the future.