im planning on installing smoothwall on an old box and making it a hardware firewall between my wireless router and my modem, no problems there.

but i recently decided that id like to play around with content filtering (web sites) and what not. i guess im looking for a linux app and it's gotta be free. any suggestions?

i just want something that would basically intercept www requests and if they are bad (whats bad can be set by administrator) it redirects to a not-found or a no-no page

incoming content monitoring is secondary but that would be really cool. i would think it would be a lil harder though, so not a must and remember i have maybe 400 mhz and 128 mb ram tops, 5-10gb hard drive space. if required i could think about putting up another box and set smoothwall to forward to it? anyway, input would be great.