Luckily for you, Philadelphia has, in recent years, experienced a glut of hotel rooms. Although you won't get far bargaining down desk clerks, you will be able to find deals online, especially in the major chains. Marriott has three options (a Residence Inn, a Courtyard, and a Marriott) in the heart of the city. There are also two Sheratons, two Park Hyatts, a Four Seasons, a Ritz-Carlton, a Sofitel, and a Loews, and a W is on the way.
House Swapping -- House swaps are a great way to get a local's perspective on Philadelphia. HomeLink International (Homelink.org) is the largest and oldest home-swapping organization, founded in 1952, with over 11,000 listings worldwide ($75 for a yearly membership). HomeExchange.org ($49.95 for 6,000 listings) and InterVac.com ($68.88 for over 10,000 listings) are also reliable. Still, good old www.Philadelphia.craigslist.org wins the popularity contest, when it comes to all things swap-able.