unless it is a specific research issue, only after 3:00 PM when "school hours" end. Basically I have a household rule that no TV, computers, DVDs, games are on before 3 pm. in part for my own sanity as I hate the background noise. It does get them reading more books, too, to not have screens on during those times.
yesterday we used an online medical encyclopedia to do some research, but generally the kids go to lego.com, starfall.com, and nick.com to play after 3.
of course in grand hypocrite fashion I get to read MDC during school hours!

: