If you're in Washington, DC, do NOT miss the Smithsonian Institution - which must surely be one of the world's greatest cultural treasures. You'll need at least two days to sample the 15-odd musuems sprawled around the gracious National Mall. There's something for everyone, whether you need the dinosaur bones and kid-friendly interactive displays at the Natural History museum or want to get a taste of space, with the Appollo lunar module and a chance to walk around inside SkyLab at the National air and space museum.
The Smithsonian's museums are easily accessible by subway (hop off at the Smithsonian stop on the blue and orange lines) althoug you'll need a bit of stamina to walk between them. As with all major attractions in Washington since 9/11, security is tight and you'll have to go through a security process at each location. This can be tiresome, especially in winter with all the trappings of coats, boots, brollies etc but a smile (and no jokes) is the smoothest way through.
Most of the Smithsonian's museums are open from 10am to 5:30pm, and best of all, entry is free. For more information, log on to www.si.edu or call (202)633 1000.
Unfortunately, the Portrait Gallery and American Art Museum were closed for renovation when we visited, but there are plenty of other choices. The African Art Museum is an absolute must-see.
The only disappointment for us was the newly opened American Indian museum. Perhaps they haven't finished stocking it yet, but we found this architectually exciting building almost empty and uninspiring. Spend your time elsewhere - especially if you have kids.
One other word of advice - plan ahead if you want to eat! While the Smithsonian boasts more than 140 million artefacts, we found a decent feed hard to find. Your best bet is the food court in the Natural History museum, where quantities are large and sugar content is relatively low. Go for soup and salad. If your kids will only eat pizza, buy one serving - they're about the size of roof tiles and will easily satisfy two to three little kids' appetites (and it's only a few metres' walk to the dinosaur afterwards...).