Ignore Rallispec, his method only works on a LAN, or WAN on a private (leased)line, if you want to go through isp's the situation is totally different. The only ways I can think of would be to either get your isp administrator to have your two address linked as a virtual lan though his network(he probably won't or doesn't know how too but it can't hurt to ask), or virtual private networking(VPN). I've only seen VPN connections used for connecting to database servers so I'm not 100% sure this is what your looking for. If you have local phone connections(assumes you both have modems) you can simply purchase 2 copy's of pc-anywhere and dial in to each others computers for direct file sharing/trouble shooting, albeit slowly. This works long distances too, but you have to pay the phone company long distance charges. If he lives in a line of sight with your house you might also be able to creat a bridged link with wirless(rubber ducki) equipment, and create your own MAN(metropolitan area network). OS doesn't really matter but since both of you XP(pro I assume) you can create a VPN rather painlessly(XP home is stripped of this functionallity without 3rd party software). This was a little winded but I wanted to show all the possible options and help as much as possible.