For users higher in a sharing hierarchy, the "My Team's Best Bets" view will give visible to leads owned by those who are underneath them in the hierarchy. This may be useful for you.
You may already know this, but if you go to a Leads View, say a view which has ALL LEADS, the reps can sort the leads based on various attributes (Created Date, Urgency, Score etc.). I especially love this since a rep can view all leads, can see the lead's score and further sort them (since the Sales Insight dashboard doesn't allow you to sort the leads per say).