On Rentalic (which just recently launched in beta), you can list things you want to rent out to others (an easy way to earn some cash) and you can put in requests for things you need.
When you do a search, you're also prompted to enter your zip code so that you can search easily through your neighborhood. The site looks a little sparse right now ... probably because it's only a couple days old. However, we already see a snowboard and a sleeping bag listed for rent in our neighborhood.
We love the philosophy behind the site. So many of us buy brand new things that are rarely (or never) used. Renting is a much greener way to go about getting things that we just need to use for a limited amount of time.
Would you use a site like Rentalic? Or are you happy enough posting things on Craigslist?