What is the walk like from Independence Park to the Barnes (scenic? safe?)?

Some of it's scenic, it's safe if you're okay with street crossing, and it's a bit long if it's hot (about two miles). On the other hand, you can break up the trip with lunch at the Reading Terminal Market, pictures at the Love Statue, stop in at the Comcast Center's Winter Garden for the video wall, stroll along the Parkway...

Of course, there's also the bus, either SEPTA's 38 or the Phlash.

Keep in mind that at the Barnes you'll be on your feet for hours. We've done this walk, and as Amy says, it's very pleasant if you make a point of seeing things along the way, but it's longish if you plan a museum at the end of it, IMO, anyway.

Your biggest threat is the ghost of old Dr. Barnes.

Right next door to the Barnes is the Rodin museum--largest museum outside of Paris with Rodin's sculptures. We happened upon a tour at Rodin after visiting the Barnes and the tour was quite good.

Further up the hill is the magnificent Philadelphia Museum of Art which also should not be missed.

The walk from Independence Hall can get a little seedy in spots but in the daytime should be fine.

We won't have time for more than the walk and one museum (for which we already have tickets). Thanks for the recommendations on where to stop -- Reading Terminal Market is the kind of thing we love!