I am nowhere near talented enough to know how this would work from the developer end, but I know what I would like to see as a user.
Imagine an escrow system set up to place tokens of the value of an item, or a receipt that represents trade items. This can be placed prior to agreement to even meet. The parties meet and agree on a price adjustment, which can be changed while in escrow. This can always be cancelled by either party. If each agrees, they simply use their password to release the escrow. Until both parties have agreed, no exchange would be made. In the event that it was a receipt, it could be used as a bill of sale, which legally transfers authority. Of course if you were dealing with an item that is titled, this would just add protection for both parties and keep the integrity of the Craigslist alt coin.
This would create a market where people trade things for this coin, and it would expand fairly quickly. A great deal of physical wealth would directly link to an alt coin. It would put the coin within everyones reach. I hope someone that knows how to create these things sees that market.
Please share your thoughts.