as a fanless solution to provide a lot better control than your normal home router.
or i was thinking of getting a full blown 3550 or 3560 and try to find an image with advanced ip services, but i think it may only offer base IP based on the flash of 64 megs.
of course if i got a full 3550 i could actually use it to mess around with to practice stuff.
I just set up the same model of Cisco SG 300 at work the other day and it's a very nice router (set ours up as a layer 2 switch). That said, I suggest you take a look at Cisco's emulators to get a feel for interacting with it since I couldn't get to the familiar Cisco command line. Keep in mind that you may have to both telnet into it and deal with the web interface as they both have configuration options that the other doesn't.
All in all, it's a great piece of hardware to set and forget but if you want to practice configuring a layer 2 or 3 switch through the command line, it's not the right choice. That is, of course, assuming that there isn't a firmware update or sidegrade that grants that interface. I didn't update the one we got.