I wrote an R function that updates the version number of a package in another question. I work a lot with GitHub and RStudio, and it would safe me quite some time (plus be much more precise) if this function was automatically run every time I opened a certain project (or better yet, make a git commit/push, but I assume that is harder to do). But I don't know how to do this or if this is even possible.
I could use .Rprofile to run R codes every time I start R, so I could just update versions whenever I start R (or build in that it only updates the version if the date is not today or something) but that seems overdoing it.
You can make a separate .Rprofile for each project. You have to put it in the main directory of the project (http://www.rstudio.com/ide/docs/using/projects).