Yeah, I've been playing this game a lot lately. Partially MP, but I also recently started my own SP world. I've built my main residence into the side of a mountain, dug a mining shaft and found an absolutely enormous network of caverns. And my last project was building a sky farm to get some regular food production.
I'm really still gathering resources for the most part, especially iron. I always need more iron. Especially since I plan on building a minecart system next.
Not much to see yet, so no screenshots for now.
I've also been watching a few Let's Play Minecraft series on youtube. X's series in particular was very nice.
And that's the door into Hades Station, my underground base built within a massive cavern complex. It's from here that I've based my search for diamonds. So far, I've found 2.
How long have you been searching? I found 14 diamond just yesterday in about two hours of cave searching, plus 477 coal, 35 gold, 124 iron and 504 red dust (well, I mined 477 coal, there's lots more), then my inventory was full, my diamond pickax had broken and I was out of arrows so I headed back up. Generally I find diamond near lava.