NoDrops is a plugin which prevents drops from spawning into the world, And gives you the feature of clearing existing drops from the world.
Its mainly aimed for building a map without the worries of players finding items you didn't notice. However you may want this as a one off job to get rid of those drops which are lagging you or bugging you.
Or host a creative server where you build, But you do not want people dropping items and creating lag.
/nodrops <enable/disable> - Speaks for itself, This can disable or enable the drops not dropping.
/cleardrops - This removes all drops in the world.
To use both the commands you must be op'd.