While I agree with UberGerbil 1000%, it's important to remember that ANY form of encryption will stop 80 year old grandmas from accidentally connecting and eliminate most devious people without a lot of knowledge on security. Often it's not the smart, well-read and experienced black-hat that gets into networks and causes problems, it's just some kid that connected to an unsecured network or uses some program he finds to bust WEP. Especially the less-dense the population is around you. If you live downtown in a big city, WPA2 is REQUIRED imo. If you live out in a quiet lake-town or something, you could probably assume the chances of some ultra-devious black-hat or war-driver is pretty low.
I would not personally bother with WEP (although again, it does stop the common person), but WPA is fine still for a residential network that does their important business over SSL and has nothing to hide. And putting in the code on 2-3 computers only takes a minute or two, even if you update preferred network connection order at the same time.
Obviously a new router w/ WPA2 should be installed in this case. But if they don't want to spend the money, even WEP is way better than unsecured: admittedly, worthless against anyone that WANTS to break in, but does prevent accidental entry (or even intentional, just wanting free WiFi entry).
Last edited by computron9000
on Sun Jan 30, 2011 5:10 am, edited 1 time in total.