Soopsoop.... there is a HUGE amount of back history about the now-famous Suby front-end clunk. In the late 90s, it was supposed to be solved by a damped u-joint kit for the steering, then in 2000 the Technical Service Bulletin (TSB) 04-09-01 was changed to reflect it being a problem with differential hydraulic pressure in the steering lines resulting in clunk when a road impact forced the wheels slightly to one side or the other against that pressure. I have a 2000 Outback and had the relevant update done which replaced the steering lines with a new factory crossover type, however, this never stopped the clunk.
One thing to check... if you are traveling very slowly, and turning, and make contact with a road bump or a driveway threshold, such that one tire hits the bump before the other, listen for that clunk. You could always have some other problem... bearing, strut cap, loose rack, loose sway bar links, etc. But changes are, you have just discovered one of the Subaru quirks, that annoying front-end clunk, and for all the info on the forums, I haven't heard about much success with getting rid of it. For anyone reading this who knows otherwise, please correct me and send the latest update, as I am tired of hearing it on my Suby.