This layout spatially communicates information about many relationships. It is formed of columns representing contacts' groups. The column contains people's cards. Every card moves within the column from left to right as time goes by. Hence, people you haven’t talked to for a while will move to the right border of the column.

That configuration visually represents 3 properties: a) Different groups — in columns b) Days since the last talk — x coordinate within the column c) Sorting by custom characteristic — y coordinate within the column

That way, you can assess a lot of relationships in a glimpse.