First off, congratulations on starting a FIRST Team!
My fellow programmers and I have had a similar problem of not having code when another needs it. You can try dropbox, which is a free cloud storage website. It allows you to store files on the cloud like google docs, but stores any file type. It's free unless you wish to purchase more than the free 2 Gigabytes. Although the simplest solution is to have everyone save on their flash drive.
And if the problem is that someone doesn't have something to do because their work depends on someone else, there's always something to do for a robotics team. Have them organize some tools or practice skills. There is always work for FIRST members to do!
