Name something you just HAVE to do in Beijing to experience it. (nothing cliche like Great Wall)
Maybe a certain hidden street to walk in, a local bar, or favorite place to shop.
I'm pretty much winging it but I just want to get a general idea of some of the things in Beijing. Most likely will be going Xi'an by train but we'll see how I feel and where the road takes me from there.

Eat bugs or scorpion in the Wanfujing night market....

PC

mm sounds good lol.. Heck why not.

Check out Nan Luoguxiang near the Bell Tower for drinks and food (the Pass By has great food). Also stop in Grifted for some souvenirs you can't get anywhere else. Beihai park is always nice. And head to Temple of Heaven early (9am should be early enough). Do NOT go to Houhai--nothing more than a bunch of annoying hawkers and overpriced bars and restaurants.

I think you will be interested in:
Forbidden City - http://www.chinahighlights.com/beijing/ ... n-city.htm
Temple of Heaven - http://www.chinahighlights.com/beijing/ ... heaven.htm
Badaling Great Wall - http://www.chinahighlights.com/greatwal ... atwall.htm

Do not go to the Great Wall at Badaling--too much of an annoying tourist trap. Go to Mutianyu. It's still be rebuilt, but fewer tourists and vendors. It's also a more difficult walk up the mountain. Once you get further up (around the 3rd guard tower) the crowd thins out to almost no one else. If you're up for a good hike, you can easily spend a few hours there.

A similar area of the wall is Simitai. It is a challenging walk along the wall and very beautiful.

Photochick

I second Simitai!

If you know anyone who drives a Harley Davidson, seek out the shop in Beijing-no cheating-no taxi! My dad rides and I have to pick him up a tshirt in every country I visit. It's never anywhere local or easy to get to and most of the time, it's quite an adventure to find it!

Go to a noodle shop! I can't remember the name of the one I went to, but it was definitely exciting. The place was packed with locals, and they sit you down at any table with an open seat. So you're bound to meet new people. They don't write the orders down, either. They just shout them back to the cooks....so yeah, it's kind of cool.

go to the art district 798, it has some really great exhibits!