Engine Maintenance 101
I can't believe this topic has generated so much discussion, considering it should have been one of the first things learned about vehicle maintenance! I don't think I have ever seen an oil filter that didn't have instructions printed on the side.. 1) ensure old gasket didn't stick in place, 2) put a film of NEW engine oil on NEW oil filter gasket, 3) twist on until gasket makes contact, 4) turn an additional 3/4 - 1 full turn. Just for grins, I went out in the garage and looked at some of the oil filters I have.. Fram, Purolator, Bosch.. all have the instructions printed on them, and all say 3/4 to 1 full turn after contact. That by the way is just about the limit of what you can do by hand, so no need for a wrench when installing.
As for removal, all the methods already discussed will work.. some better than others. I have 5 or 6 different oil filter wrenches in the garage, and have used the screwdriver method as well. Most of the time, it's just a matter of how much clearance you have that determines the method. The best I have found for tight places is the one that uses a standard 3/8 socket wrench and has three spring loaded fingers that grip tighter as you turn.
Harbor Freight has them for about $8. Soft-strap wrenches also work well if you have the space.. if not, the
rigid strap with swivel handle types can usually get in where the soft strap ones can't. The pliers type as well as channel locks will work, but you need enough room to turn them. Save the screwdriver for method of last resort!
http://www.youtube.com/watch?v=sxSya1YNMKI
Cheers,
Brad