intercepting data on my network

[crazyanimal]

Ok let's say i am on my network at home and i want to see what someone is looking up on my wireless connection. Is there a good program ("free" is good) that can list them by site name or even IP address. at the same time drop the unnecessary packets? i have wire shark running and man to dig though all of that data for websites visited, makes me want to scream and go back to drinking and smoking. lets just say that i am really after IM messages and such from a, believed to be, cheating wife. any help would be greatly appreciated.