I think you should consider using a project/collaboration tool instead - having a website costs next-to-nothing and its a pretty acessible method.
http://www.php-collab.org/ is one I kinda like - great tool anyway both for employees, contractors and customers. (got a demo site if you want to take a peek)
For more closely relating systems, I'd say go for pocketpc's for everyone and an Exchange server to coordinate it. It's small, handy, and really can do what a 'real' PC can do - advanced calendar functions, coordinations of meetings and bookings, surfing info from the Net, keep track of miles on the pocket excel, send and receive emails... OK I only use mine for half those things, but I love it. It's some ways from freeware... but when you have it, theres no end to the freeware you can
get for it, just look at TotalCommander...
