My 16 year old and I will be in Philly in June on a Friday, Sat and Sunday morning. So far on Friday we have: Independence Hall, Liberty Bell, Constitution Center, Christ Church burial ground, Elfreths’s Alley and the Lights of Liberty. We are trying to decide what to do on Sat. The Philly Museum of Art, Ghost Walk, Valley Forge? On Sunday, we do have tickets for the Barnes Collection. Did we leave out anything important? Is this a good itinerary?

Sounds like quite a full itinerary, although the things you've planned for Friday are walkable and close together. I'd just keep an eye on traffic for a trip to Valley Forge. Traffic bulletins are broadcast here every 10 minutes on AM1060 on the two's, as they say (1:02, 1:12 and so on).

You could easily do Valley Forge in the morning and the Art Museum in the afternoon. Right now there is an Andrew Wyeth exhibit there and it is very good. It's open until 7 on Sat. My teens really liked it as well. As far as eating out....my kids love the Continental. There's one at 2nd and Market and another at Chestnut and 16th??? (not exactly sure of the 2nd one). There is also the Franklin Institute and Zoo if you don't want to go out to Valley Forge...they have a new exhibit. Have fun.

i grew up right next to valley forge park and higly recommend it. however the franklin institute is really fun too.
you might combine your barnes day (and fyi enjoy the current location because politics is forcing them to eventually move to downtown philly which in my opinion will change the experience completely) with valley forge as they are generally in the same direction. you could take the train to merion, do the barnes then hop back on the train to say wayne. i guess you would have to rent a car for the day at that point or perhaps could find a taxi driver that would give you a tour.

For your Philly itineray go online and get tickets in advance for Const. center and Indepedencce Hall. If the line to see the liberty bell is huge, I would skip it.

If you are looking for something to do Sat. evening, Comdey sportz (improv comdey show) is fun and is done so the whole family can enjoy it.
http://www.comedysportzphilly.com/

You could combine a visit to Valley Forge with some shopping at the King of Prussia Mall.
Go to www.gophila.com for some great info on acitivities.

I'd def do the art museum! It's great and so much to see. The Philadelphia Zoo, too or the Franklin Institute is fun. Sat night maybe do the ghost tour. I always meant to go on one, but never have.

IMO, valley forge isn't all that interesting unless you plan to ride bikes there. I'd skip it unless you're really set on going there.

Visit Reading Terminal Market on Saturday morning. Have breakfast at the Down Home Diner in the market. Visit the Art Museum and then perhaps go over to Rittenhouse Square and have some gelato at Capogira's (arguably the best gelato in the US)You could then walk down Walnut Street where there is some shopping, and perhaps stop in and see the Kimmel Center on Broad Street. Have fun. Oh, I would also skip Valley Forge with just a few days to spend in the area.

Cut Valley Forge - you can wind up stuck in traffic, even on a weekend. Although historically important, Valley Forge is a disappointment unless you are a die-hard Revolutionary War buff - it's just a huge field with a few cannons in it. I have never heard anyone say anything great about a visit there.

The Philly Art Museum is free on Sunday, if you want to make that a museum-filled day. I would also recommend Reading Terminal Market on Saturday - many choices for a great lunch.

You and your 16-year-old might enjoy a stroll down South Street (between 2nd Street and Seventh Street) on Friday or Saturday evening - it is a "funky, off-beat" experience. You can have a cheesesteak at Jim's Steaks at 4th and South.

If you and your 16yo like books, consider a visit to the Rosenbach. One of Philadelphia's overlooked gems.
www.rosenbach.org

Also, I heartily agree with Suki about breakfasting at Reading Terminal on Saturday...BUT I say go to the Dutch Eating Place instead of the Down Home Diner.