Another little project I have been hacking at, the ability to have a record "lock" when it is opened to avoid save collisions. So...
User A opens a record
User B opens the same record, it is "locked"...fields are read-only, buttons and action menu removed. Note that we could still create activities and all the functions on the Nav Bar, but hey this is a POC! :)
User A closes the record
User B can now edit
As long as user A has the record open, it will stay locked.