Embedded PC with Gigabit Ethernet and SD card interface?
Check out RouterBOARD -- These are custom designed hardware meant to be used with the Linux-based MikroTik router software, but no reason you couldn't put your own software on there. You didn't really say anything at all about your application, so it's hard to give a specific recommendation, but the RB750G is a good combination of price &amp; power I think. 680MHz CPU, 32MB RAM, with 5 gigabit LAN ports.