There are 3 macro options for charging the Tesla Model S. You can charge the car at a residence, at a public location free of charge (pun intended), a public location for a nominal cost.
When I picked up my Tesla Model S, I only had a standard outlet in the garage to charge from (long side story there). Plugging the car into a 15amp 120V regular wall outlet will recover 2-4 miles per hour of charge. Given my experience on range, this just barely keeps up with what the car uses to keep itself alive when not being used. Until the
High Power Wall Connector is available, I've installed a 50amp 240V circuit for charging(UPDATE: Installed the HPWC on an 80amp breaker and getting 43mi/hr when charging). The 50 amp outlet recovers 26 miles per hour of charge ... 10 times better than the standard wall outlet - and possibly adequate for most people. You will want to seriously explore moving from flat kWh billing from your electrical company to hourly billing via a smart meter. At the end of 2012, we saved over $625 which was 50% savings compared to what we would have paid under the fixed price structure. As of May 2013, the savings were $1,095(~51%) compared to fixed. We had some heavy electrical usage in the evening to begin with so our savings may not be typical, but ComEd reported savings on average of 38% for the year for all participants across the program. In Illinois, call ComEd at 1-888-202-7787 for more information. The electrical companies charge more for electricity when demand is high (6-9pm as an example) and less when demand is low (1-5am). For me, peak demand average price could be .11/kWh where non peak is generally .02-.03/kWh. The problem you will find with hourly billing however, is that the Tesla Model S Charging starts as soon as you plug in the car unless you tell the car you want it to start charging at a specific time. So, if you get home at 6pm and plug the car in then, it starts charging at peak rates. I've configured the car to charge at 2:30am. I plug it in when I get home around 6pm and it starts charging at 2:30am and I have a full tank by 5am. I've run the numbers multiple times as it doesn't seem real, but compared to my V8 sports sedan with gas at $3.76 (11/2012) ... each mile in the Model S costs about 2.5 cents/mile versus ~22 cents/mile in V8 - MY equivalency here is about 150 MPG versus Tesla's MPGe of 85-90.
Tesla Model S charging in public is an excellent option. There is a network of charging stations in the Chicago area managed by
chargepoint and depending on the specific location, the power may be free, included with a parking fee, or based on an hourly rate ($2). Power in these scenarios is for all electric cars, have the J1772 connector on the end (bring your Tesla Model S charging adapter) and they run 30amp/240V which will get you 14-16 miles per hour of charge. My town has a free charging station 1 block from the train station in a paid parking lot (EV's are free if they are charging) and this alone saves me a 10 minute walk from where I normally have to park to catch the train (and pay $1.50). There are parking garages downtown that have charging stations (again premium parking right as you pull in). Some include free charging with the daily parking fee, others are in addition, so research this with the
chargepoint website or iPhone/Droid app. There are 3 different ways to use/activate the charging stations. The easiest and quickest is to register on the site and get a smart card from
chargepoint (using your own chip embedded credit card should do the trick as well although I haven't done that so can't comment). Doing this requires you to provide a credit card and seed the account with some money. Starting a Tesla Model S charging session from the iPhone app is easy, but it takes a few seconds for everything to get started (and you need an account on file and an activated card, even if the charging is free). If you don't like the idea of getting a card or creating an account, you can always just call the number on the charging meter and give them the meter number and they will turn it on for you as long as you are at a free meter. They ask your name, email, etc. but it's a relatively quick process - not as quick as waving the card. I've used all methods and prefer the card myself. You may want to sign up for a card two weeks in advance of taking delivery of your Tesla if you have chargepoint stations in your area. I wish I would have had one when I took delivery and didn't have a good charging solution at home. When you register for the card, you can configure messages that the network will send you about your charging session. I especially like the message that says 'your car is drawing very little power and may be fully charged' or 'your car has been disconnected from the charging station'.