I'm alone on thanksgiving and I figured it would be a great opportunity to get my geek on...

I snagged a box off of ebay, I was going to buy a router but this was cheaper and I always wanted to run a pfSense box.
Its a 1U server, I swapped the +12V and +5V rails for the case fans so its pretty quiet. It has:
2x 2.66GHz Xeon w/HT
4GB RAM
40GB HD
2 1Gb Intel NICs
1 10/100 Intel NIC
I figure that should move some packets. I plan to ignore the 10/100 port and have one Gb interface as WAN and the other as LAN, does that sound legit, what else can I do with that wayward port?
1.2.3 vs 2.0 Beta4, what should I run?
Do I need to do anything to turn on the web interface?
Anyone have any tips or tricks or know any gotchas?
Am i missing out on anything by using the default/easy install option?