How can one setup a version control system on a local network, without a server?

Edit: Ok so I learned that I guess I need an distributed source control, however are there any UI based ones, and do they allow you to merge with other users on the network?

This is kind of a two part question, so here it goes. I want to start developing a web application at home (with multiple developers). However, I don't have a dedicated server nor want to pay for on.

So first, I don't know which version control system to use for this case, as at work we mostly have TFS setup, so I am not to familiar with whats out there. What are the best free CVS/SVN tools out there?

Second, is it possible to somehow setup the CVS/SVN where there is no dedicated server and both clients store up to one week of the source code from the last check-in?

Also, it would be helpful if it could integrate with visual studio, again this isn't that important at all.

Problem:

There are Five users, one is a Server.

Server Connected: All Ok

Server Disconnected: No one can share.

What I am looking for:

No Server:

1. Users still have versioning based on version id of last check-in.
2. Users must check all version on network to make sure they aren't outdated based on their last version id.
3. If not check-in, otherwise merge/get latest.
4. If they are update checkin, and set current version id +1.

If your looking for a source control that DOESN'T have a central repo, you are looking for a distributed source control system such as Git or Mercurial.