I just thought up an interesting, albeit slow, fuse/trap/mechanism. Using Netherrack as a long-standing torch, give the torch (which would be inside a tomb of your design) a wooden ceiling/hidden placement surrounded by stone to hide it in the darkness, set it in a way that your only choice is to use flint/steel to set it alight, and make use of the fuse as a sort of timer device. If you run out of time, the sand/gravel floor will begin to collapse.
I think this would work best in a sand castle/dungeon; and the requirement to light up the torch would be to either open up a hidden door (regular sand that drops like the rest of the main floor), or a wooden door that gets burned off by the radiant heat and opens up the dungeon, as well as sets off a fuse that gives you a ;limited time to solve a puzzle so you can mine out the obsidian exit with the diamond pickaxe at the end of the dungeon. Of course, that will take limited time as well to achieve. I dunno.
Good use of MCEdit and setting up the sandcastle foundation drop trap and fuse with it is necessary. This is designed to be a slow fuse/trap unlike the swift water/torch drop method.
I may need to take a moment to craft some samples of what I'm talking about. but overall, if it works how I envision it to, it should look really cool when it triggers.
One way of making and hiding it is making a sand/gravel floor and ceiling sandwich with the wood (hidden between and above/below the netherrack torch (in this case, below the netherrack block)). The radiant heat will burn the wood beneath the netherrack, and slowly burn the connecting wood blocks until 1 sand/gravel block falls, causing a chain-reaction of falling sand/gravel. This can be used to interesting effect. Secret passageways anyone? Or total dick move traps?
EDIT:
These slow fuses can also apply to TNT traps as well. Ooh, this can be used for many a nasty idea.
EDIT EDIT:
Just tested a couple concepts. Unfortunately, it doesn't work as I thought it would. Oh well. We might still be able to make drop-traps however. Fire climbs upward, so upward fuse, destroy a wood block with it, drop a sand block onto a pressure plate that activates a redstone insta-fuse.
Did Notch change how fire works with any of the updates? Oh wait, we can still use leaves as fuses, provided a wood block once in awhile to keep them lively. Anyhow, as impractical at times it may seem, creeper dust (gunpowder/sulpher) should be placeable as a fuse that can be lit up, unlike redstone, it has a delay and must be lit.
Alternatively, we can always use magma tiles that can be cut off at a certain point, as to not flood the tomb with magma, as well as still activate traps. On that note, have it setup as a trap in itself, where you have a series of torches encased in stone and 3 windows, except you have to make the right choice, as some ceilings of those will drop sand immediately on top of the flame, and put it out, or collapse the fragile sand/gravel ceiling, or let loose with a sample of hell and flood you with magma (or a fake-out with water in the dark; water/magma source tile to entirely flood); or a combination of a sand/gravel ceiling collapse with a magma/water chaser.
EDIT EDIT EDIT:
The collapse-a-fuse worked wonders. Netherrack, wood ceiling for the lantern, sand planted right on top of the wood that burns off. sand falls and chains with the rest of the sand it's linked with, reaches the collapsable sand ceiling with magma atop it, area is now a magmarium. Mind you, the trapped ceiling with the magma was sufficiently high enough, and the lantern was a pillar that reaches up to the ceiling. I would suggest about 5 tiles of height minimum.
When I have the time, I'll see if I can make a testing ground so you can see some of my ideas that wood burning and sand-fall trap combos can show potential for. Someone has to make an Egyptian tomb or something.The front door is the only way in, and let's say two main treasures are needed to get out. One treasure chest contains enough ladders to exit from the bottom of the tomb out to the top of it, or out of a sphinx's nose, and the other treasure chest has diamond equipment. You start the tomb with only a few torches (let's say 4 of them), some torches can be taken (some rigged to trigger traps), and you will have to burn some doorways or bridges or something, so a steel ingot and a flintstone will be in different chests in the tomb. This is when the cool/fun parts come in, where you have to light the right torches to trigger the right traps and open unseen paths (some sand-falls go a long way from one end to another and drop a high-up sand block onto an arbitrary spot in the main hall's sandy floor (one would be nervous here anyway), and open a hidden ladder passage deeper into the tomb.
We gotta do something about this. Maybe it should belong in Creative Projects?
Mine Raider: The Adventures of Lara Craft
:Cowers as he's beaten to death for his puns: