Just thought I'd post about my server, a vanilla SMP.
Build a shelter, build art, join up with other people and have war- do whatever you like, as long as you don't break the rules.
Rules:
No greifing
Don't fight people who don't want to fight
Don't steal
Don't spam
No cursing/vulgarity
Just use common sense and you'll be fine.
Unfortunately, it's not 24/7. But if you'd like, add my server to the server list so you'll know when it is and isn't up.
Join at 173.25.106.245