I'm currently building what I'm calling my "great western highway"; a lava floor lit road, six blocks wide, about ten to fifteen blocks above sea level and equipped with two lanes of railway with the intent of creating a fast and safe path to a new biome. I'd already explored the world for quite a ways prior to the Beta release so this is a huge push out to virgin lands, hopefully with pumpkins and that blue ore stuff. Needless to say it's seriously taxed my glass and coal reserves, eaten three diamond pickaxes (I tunnel straight through the mountains) and involved countless trips back and forth the the nether (a portal to which I conscientiously placed at the Fort Binky terminus) with buckets and buckets of lava.
Fortunately, the tunnelling through the mountain part provided enough extra iron, coal and cobblestone but wood is becoming an issue. See, I went and stored some lava in a pit a little too close to the forest of trees I'd planted in preparation and...well...the forest isn't there any more. On the up side, as you can see on this map I'm getting close to snow, and the edge of the explored world so hopefully I'll be able to finish it!