Since the topic cames up from time to time, I am putting up some sites on some filters that fit right in.  These sites are for filters that offer extended use of the oil (falls right in with synthetic oils) .  I have been collecting some data for a while  but really have not had the time to actually try one of them.   Some of the people on this list have a little experience with some of these and you might pass along some of the information so that newer members of the list can be enlightened. 
 
http://www.garynorth.com/y2k/detail_.cfm/5359
 
http://www.p2pays.org/ref/01/00124.htm
 
http://www.oilshop.com/amsoil/amsoil.bypass.htm
 
http://trasko-usa.com/
 
http://www.gulfcoastfilters.com/
 
William