E.B. and Simon Prunet have done tests to check the speed and ease of configuration of 2 Linux PCs connected through a crossed ethernet cable (100Mb/s Fast Ethernet). We manage to get 12 MB/s sustained as expected. The next step is to do the same between 2 PCs equipped with Gigabit ethernet interfaces. Note that crossing should not be necessary for GbE, as all four pairs of cables are used in both directions.