We use Business Objects Enterprise XI-R2, and there's no built-in way to back up the individual reports. We do backups of the report file share and the database, but if somebody deletes a single report, they're screwed unless we store everything to a standby instance and retrieve the report, which takes hours.
Is anybody out there doing a report-level backup of BOE, or is there an easy way to use some kind of source control system to allow for restoring a particular report?
There's nothing to stop you checking them into a version control system like SVN. However, I would say that you should check them into an entirely separate repository, don't try and share it with a repo that developers use for code, it will get very large and make it difficult to backup up their source. Is it possible for you to share the volume for the reports as read-only? That would stop accidental deletions from happening.
See this discussion over on Stackoverflow Version control for binaries