Strategies to avoid conflicts in xcode project file?

Once a week or so, I add files to my xcode project at the same time as someone else, and we get a bug ugly conflict. Often this conflict is easy to resolve, but sometimes it gets a bit nasty. How do you all deal with this problem. What I do is:

Try to remember that any time I'm adding files, I'm in grave danger, and must remember to update and commit immediately.

One thing I've thought of is to have something alert me whenever I save a file -- have sirens, flashing lights, etc, and a giant message popping up on my screen saying "idiot, don't forget to commit right away!". Any thoughts on the best way to make this happen?

Any other ideas on how to avoid my weekly headache?

What about using svn:needs-lock 开发者_StackOverflow中文版on the project file? Might that work?

Treat the project file as a binary file (i.e. tell your SCM it's a binary file). This avoids conflicts, but also requires that your co-workers re-add the same files you did. Not ideal, I know....

Another idea: work alone? :-)