While I've got a mini P180 for my main rig (smallish), it's firmly ensconced within its desk enough that I don't move it. For LAN's, I unplug my HTPC (which is now an ex-HTPC, displaced by the new DVR 🙁 at the fiancee's request) and easily bring it around.
nsk1380
Intel dg31pr
e8400
9800 GT
2x2GB RAM
1x500GB HD (room for two more)
1xmulti-DVD thing.
and your random wireless card
I've discovered though, through LAN's, that it gets a bit choked up on heat after a couple hours 🙁