This is a short demo of the new redstone repeater block added in Minecraft Beta 1.3.
The block has three uses:
1. It "repeats" the redstone signal, as a network bridge. It has the same use as two not-gates, but will repeat the signal slightly faster.
2. It works as a "diode," meaning the redstone signal is only repeated in one direction.
3. It has a configurable delay, which allows you to change how long time the repeater should wait until it transmits the signal. The delay steps are currently 1, 2, 3 and 4 (in multiplies of a redstone torch delay).
You can still use normal circuits to delay and repeat signals, if you want. In some cases, it will still be more space-efficient to use not-gates.