I know a Mob Spawner seed! It's called, "theworstseedever". Look around, there will be a big rectangular hole in the sand, and there will be a zombie spawner under a block of sand in the middle of the hole.
Bedrock can be destroyed with enough TNT. It's impossible to collect, however, as it will be destroyed in the blast. If Minecraft crashes because of all the TNT, then it'll go back to your last save, before you tried to destroy the Bedrock.
When you run out of things to say, come up with something off the top of your head.
The seed "404" blast you into a peaceful looking world, if you break a tiny bit of gravel, all of it will fall to show a huge cave system. There is a challenge for it, look for it on the forums.
OMGZZZZZZ! ! ! ! ! I know how to duplicate items without a program!
Duplicating:
1. Go to your inventory, drop your items you want to duplicate by clicking and dragging out of the inventory menu.
2. Save and quit to title.
3. Load back on your save, and pick up the items from the ground that you dropped earlier. Then you have about 2.9 seconds to close the Minecraft window. Log back on Minecraft and "volla"! Your Items are duplicated! You can duplicate as much as you wish too.
Warnings
1. Sometimes, it may not work, and you'll have to do it again! This is because duplicating is a glitch, glitching is confusing the device.
2. I think you have to do it with a roof over your head (Your house). I'm not sure... I tried it out of my cave house and it didn't work.