There is a useful thread in the HK section on what to do on a weekend in HK, you can probably do a truncated version:

http://www.flyertalk.com/forum/hong-...e-what-do.html.

Based on your 6 hour layover, your "real" time on ground will probably be closer to 4 hours, which, depending on what you want to do, is doable.

What do you want to do? Shopping? eating? drinking? sightseeing? massages?

These options can be done in 4 hours (might be tight to do all of them though). Rushed? Maybe, but easily doable.