Freecycle is a great idea; giving away stuff you don't want to people happy to come and take it from you.
The problem is that Freecycle operates via mailing list, and isn't very well suited to it, especially when subscriber numbers increase beyond a hundred or so. Suddenly you're being swamped with messages and it's very hard to keep track of the status of any particular offer. People end up sending many unnecessary messages finding out if something's gone, is still available, and so on.
What Freecycle could benefit from is a neat little webapp to make the process simpler.
Let's say we start with a home page at freecycle.org - something nice and easy to remember, much better than the Yahoo! Groups URLs that members currently have to deal with.
Local Freecycle groups could all have a subdirectory of that, perhaps also subbed within a country dir, such as freecycle.org/uk/bradfordonavon.
On this page, logged-in members would see a list of current offers, colour-coded with the status. Pale green background means on offer to all; yellow background means reserved and awaiting collection. Red background means taken; these items will drop off the bottom of the list fairly soon after being snapped up.
Each item is controlled by its owner. When you log in, you have access to another page called "My items" which shows everything you are offering or have claimed.
Making a claim would work a bit like comments on a web page, but only the item owner would see all the claims. Other members would see only their own claim, along with the total number of claims made by others. Such as: "You have made a claim for this item. There are 5 other claims."
A successful claimant will be chosen by the item owner simply by ticking a checkbox next to their name; a message will appear in their "My items" page informing them that they've been successful, and perhaps they could optionally have an email sent to an address of their choosing with the same information.
Freecycle's ingenious concept is constrained inside mailing lists. I think that a well-designed webapp along these lines - almost an eBay without the payment involved - would go a long way to freeing it up and getting more people taking part.