My guild has run multiple Minecraft servers in the past few months, though I got the game myself back in August. I went through a huge building phase on my guild's first server, which had give commands enabled, so I built... well, a huge, floating castle made out of snow and diamonds. Alright, so maybe my feminine side comes out at times.
To redeem myself, I also built a pirate ship and an obsidian guild hall with one of my friends. The guild hall had our guild emblem glowing in the middle floor as magma encased in glass. It was a super imposing structure... and missing placing a block of obsidian is one of the most painful things to reverse. Whack, whack, whack, whack...
Anyway, the newest version of the guild server was started recently and is restricted to "true" game play, where everything has to be scavenged, hunted or mined. It's really almost impossible to tell there is any restrictions, though. With 10+ motivated people working on structures on the server, it seems like quite the little society! There is a huge tree-fort, multiple island castles, an outdoor residence (exclusively lit with glow stones), a snow fortress, and many more wonders!
My own creation has been fairly small. I found a nice grove where some trees had grown together, so I built a wall around it, then made the wall a hallway and started working on towers at the corners. Of course, someone from the guild encouraged her husband to build his house right next to mine (the nearest underground area coming withing two blocks of my walls!) and then built a bridge directly over my courtyard (and just a few blocks above the top of the walls). This went right over where I was building a tower so... well, I tore the part that was in my way down. I planned to rebuild it a bit, but then I noticed it was 5 am and that I was dying of sleep deprivation. Thus, when I logged on this afternoon, I was informed by my guildmaster that he would really appreciate it if I fixed the bridge because he had gotten complaints from the two. I can understand that he doesn't want to take the playground teacher role, but I feel like if people are so rude/ignorant that they would build something directly over a clearly growing structure, I shouldn't have to apologize nor fix ripping their transgression down. My GM is a good guy, though, so I rebuilt the bridge with little complaint and teased him about leaving a rude sign (I didn't).
While my growing castle isn't all too impressive, I have been doing quite the tunnel work. I created a central entrance point in the middle of my courtyard that is fairly hidden under a tree. However, from there, it stretches extremely far out. In my digging I've connected my main tunnel to five other houses and numerous other tunnel complexes in the area. Admittedly, I haven't let everyone know that I've dug into their household. My tunnel came up quite conveniently under a crate in one of my friend's houses, so I ran around, then replaced the crate and continued digging.
Minecraft can really suck the life out of you! Though, admittedly, I wish it took just slightly less time to mine. I almost want to make all of the rest of my castle out of... Netherbrick? Nethersomething... Just because it only takes one hit to mine! I spent the last part of my time in the game today running around Hell and getting glow stones, soul sand and netherstuff. Admittedly, I have absolutely no clue what I'm going to use them for, but I'm sure I'll come up with something!
Anyway, Yahtzee covers my feelings about Minecraft pretty well:
http://www.escapistmagazine.com/videos/view/zero-punctuation/2680-Minecraft
Edit: PHOTOS!
+ Show Spoiler +
Part of my growing castle:
The view from the spawn point:
The arena (yes, we fight to the death there):
The new guild hall (not built by me, I don't put crosses on top of things):
The closest portal to Hell which also displays my guild's use of signs (they put signs on EVERYTHING):
Entrance to the outdoor residence, protected with a trap bridge and cacti:
Some creepy status in the outdoor residence:
The view of part of my castle (you can see one of the larger towers) from upstairs of the outdoor residence:
There should be more pictures, but I got lazy. There is a carnival going up. It already has a glass maze and will have some rides and a cannon soon! I know this isn't super impressive compared to what someone people have done in minecraft, but I don't think it's too bad for a server less than two weeks old!