One of the chasms in Domino's data model is the (lack of) ability to run transactions. I had found someone else who started a thread on ideajam. If I had penny for the times a webQuery Save agent failed halfway through a complex save process because of object variable not set I would be listed on the ASX by now. I think the start/commit transaction would be feasible within certain constraints.

1/ Runnable only  from Scheduled or Web script agents.

2/ Transaction Pair (ie Start/Commit) must be within the same sub

3/ An ability to link transactions across sub's.

Because Domino's document model allows us to support pseudo-relational links as well as response hierarchies, the last constraint is more of a feature than a constraint. Logging would be a bugger though, being able to configure a separate transaction server/file store would be needed. So how hard is it ? Maybe see it in Domino 9.0 ?