Hi there,
First of all thank you for your nice ideas!!
just let you know, there are so many filtering company's out there already for PC's and for Mobile devices.
talking about DNS: OpenDNS , dyn.com and more.. are free! (the DNS ones are server based).
DNS by it self is not the best selution, becouse the DNS IP can be changed without a password.
if its installed on the Router then it can be rest as well. it can only be good if we are talking about a server room or a router that's locked in a closet.
so a combo of server based and client based would work best.
asking me, i think it would be a waste of money for GYE inventing filters. don't forget that there is out there 'Lots' of programmers and developers working constantly on new filtering options...
you can check out here a list of filters
www.filterlist.tk/ (this list is not so clear, but you'v got some links..)
we at GYE are building now a new website for 'Prevention' and filtering,
we hope to have lots of Volunteers that can help install web filters for people world wide remotely.
if you are interested you can contact me with your info
filter.tzvi@gmail.com Thank you and All the best
Tzvi