Sub CirclesThatsmystyle77 posted about filters and I agree. I think it could be taken a step further and formalized into presets called Sub Circles. Friends could be in one or more SCs. This would allow each user to filter their friends into more manageable amounts. Then when you display recent activity you could have it filter by SC. This should make the programming easier than an on the fly filter.
Just a thought. Does anybody else likes this idea? If so it really originated with Thatsmystyle77 first. Have to give credit where credit is due.