From Applesaucers who contributed:

The fans of Shiri Appleby have purchased an ad in the February 23rd edition of Daily Variety to say "thanks" to their favorite
Roswellian. The "Applesaucers", as we are known, wanted to publicly acknowledge the outstanding and irreplaceable contribution Shiri makes as the lead character Liz Parker, and to urge everyone to watch
Roswell, Monday nights at 9 on The WB!

There is a picture of the ad on the Shiri Appleby Board which you can get to by clicking here.