I have changed ours up a bit to suit the needs and time frames for my family. Each of the 4 'big' kids in the house starts each week with 6 tickets, each ticket is worth 30 mins on the computer or game system. Homework needs are excluded from these tickets. In the course of the week there are options for earning reward tickets that do not 'expire' each week.
In the past 3 or so weeks they have cleared my brain of the clutter that accumulated from keeping track of who played the computer when and for how long.
What are your rules and strategies for equalizing computer time and limiting kids gaming 'addictions'?
Hope that your day is wonderful and that you children are lovey.