When I'm out of town I set my machines to one pool and then monitor that pool over the internet.  Controlling is another matter.  Linux is like hitting the easy button (although that is literally the only thing that's easy in linux).  You remote in to linux using SSH, which is a simple terminal program that has some really cool (and convenient) security features built in.

They do make SSH servers for windows (eg Putty) and clients for smartphones and whatnot.  If you're cool with the command line, that's one option.