Is there any way to share files between a Linux and WindowsXP machine, using a usb connection? Can an internet service be shared over a usb connection?

If u have 2 machines one using linux and one using xp then u will need a network card installed in each to start with, which u will need whether u want to file share between the 2 or to connect to the net. If u have a usb connection to one machine (along with ur network cards) then u can share the internet connection. It depends which machine u want to use for ur internet as to how u r going to set this up :-) U can not share machines by a usb cable from one to the other directly they are not able to relay the information :-)

You need a special usb cable, do not connect two compters to each other with the standard cable

Here you can find some general information:
http://www.linux-usb.org/usbnet/#t-host


Here you can find a working sollution:
http://www.geo.vu.nl/~zeem/projects/...nuxusbnet.html


PS
I personally would not invest in a special usb cable but would buy a nic for each computer and a cros cable.