We wanted to do a keeper but we didnt want to make the draft meaningless. We have it set up so when we have 10 teams you can keep 4 players and if we have 12 teams you can only keep 3 players.
You can keep anyone regardless of where they are drafted, but you must keep at least one pitcher and one hitter, cannot have only hitters or pitchers (unless you decide not to keep your full allotment of players-see below).
Since we have 12 teams right now, if an owner chooses to only keep 2 players they get an additional 5th round pick, if they keep only 1 player they get an additional 3rd and an additional 5th round choice and if they decide to abandon thier entire team they get an extra 1st, 3rd and 5th. These picks are given at the end of each round.
Doing it this way helps keep the main players on your team, but it doesn't take so much away that the draft is less significant.