I know most or all of you don't know me, but I played on The Construct server heavily around 2007-2008, and since you now play a lot of Minecraft, I thought I'd clue you into something that I think is pretty cool. It's called Tekkit.
Essentially, Tekkit is a modpack for Minecraft that expands the game tremendously. It contains many mods, but the four most important mods are: Equivalent Exchange, IndustrialCraft, BuildCraft, and RedPower.
Equivalent Exchange adds magic to Minecraft. Every item is assigned an "EMC" value, and certain devices allow one to convert items into other items based on this value. For example, stone is worth 1 EMC and a diamond is worth 8,192 EMC. Thus, if you gather 128 stacks of stone and put them in an "energy condenser" (constructed with obsidian and 5 diamonds), and you place a diamond into the template slot, you can get a diamond.
IndustrialCraft adds a number of machines and items to Minecraft. Firstly, it adds several types of armor, as well as new tools (mining drill, mining laser) and new machines (macerator, compressor). All IndustrialCraft tools and blocks are powered by Energy Units (EU), which can be generated from naturally occurring oil, lava, wind, water, uranium, or sunlight.
BuildCraft is perhaps the most interesting addition in Tekkit. It includes pipes that allow one to build automatic supply chains and production systems. For example, you can build a quarry that will automatically mine out a large swath of land and pipe the resultant product into a sorting machine that will process the blocks with IndustrialCraft machines. I know someone who built a machine that would automatically mine ever-increasing plots of land and generate solar panels which would then be placed and added to a power grid.
Finally, RedPower is a mod that overhauls (but does not replace) the Redstone system in Minecraft. It allows for custom block cutting, ceiling wires, one-tile logic gates, and much much more.
There's much much more to Tekkit than what I've listed here, and you can read about it on the Tekkit wiki.
Here's a video about Tekkit:
One last thing: Tekkit is incredibly easy to install. As long as you have the right version of Java, you can just download the launcher and it will automatically retrieve the newest jar file. It took me less than 5 minutes to install Tekkit the first time. The Tekkit (Technic) launcher is available here: http://www.technicpack.net/download/
I'm currently running a Tekkit server for a small (<10 people active at a time) internet community. Anyone who wants to play some Tekkit is welcome to join, though I am currently working out some bugs with server-side mods, so there could be some instability. The server IP is: "taktoa.dyndns-server.com" (no quotes).