yes you can. You can transfer miles from CO, DL, UA, TW and some others to Hilton at an exchange rate of 1:2, in increments of 5000 miles. e.g., 10000 DL miles will get you 20000 Hilton points. (For AA, the ratio is 1:1).

You can transfer HHonors points to the same set of airlines as follows:
10000 HH > 1500 airline miles
20000 HH > 3500
50000 HH > 10000

(For AA you get 2000, 4000 and 12000 miles, respectively).

[This message has been edited by james (edited 11-23-2000).]