DVCS-autosync

1. I want to keep all revisions up to X days/revisions ago, but I don't care much about anything before that.

2. I know that this is a good version, I want to make sure I can always see this version, but I don't care about all the other versions I haven't tagged.

3. I want to save one version per day/week/?? but not _every_ version (i.e. get me back into the approximate area, but don't spend the resources to save every version)

I can also see combinations of these

for example I want a snapshot each day, but every revision for the last week

given how efficient the git compression can be, I would suggest having a dry-run mode that will tell you how much space you are saving by throwing away the history. for binary files it may be quite a bit, but for other files you may be surprised at how little it saves.