Hm, interesting... good question!!!
Eight plates in the cupboard, eight cups, eight bowls... - I've paired mine down quite a bit, but I still have a TON more than that... I don't know!
Eight minutes on the computer at a time.... - NO WAY!!! I sit down all the time and think 15 mintues - like right now - the boys were asleep - I thought 15 minutes then I'm gonna take a shower (it's been a rough morning)... but here I am 45 minutes later - I STILL NEED THAT SHOWER!!!
Eight toys out at a time for the kids to play with (rotating frequently).... Not sure if the kids would keel over at the thought of this one... but I may have to try it! Still don't know if I could get down to 8. 8 per kid maybe???
Eight no shopping days a month (to start and build up)... Sure, since the spending freeze I've cut back on shopping all together. Last month I would have said 8 days in a week maybe

, but this month - no problem!
No more than 8 commitments per week for the family outside the home (includes church, sports, activities....) - Hmmm... this is pushing it... church, soccer for ds1, soccer for dh, soccer for me, hockey for ds1 (starting soon), hockey for dh... that's 6 right there. MAYBE!!! Oh, but once ds2 (2 yrs) & ds3 (5 mos) are older and into sports there's NO WAY!!!
Nice thought though - I'm gonna have to think about this more! What else can be done with the Rule of 8???