With everything that Japan is going through—the quake, the tsunami, the nuclear scare—it'd be sorta understandable if things like the Internet stopped working. Amazingly though, the Internet stayed up.
Renesys, an Internet research firm, is finding that the quake didn't really effect Japan's Internet:
"Today's 8.9 magnitude earthquake in Japan has had surprisingly limited impacts on the structure and routing dynamics of the regional Internet. Of roughly 6,000 Japanese network prefixes in the global routing table, only about 100 were temporarily withdrawn from service - and that number has actually decreased in the hours since the event."
Most other earthquakes break the undersea cables that connect countries connected to one another, Japan managed to avoid those breakages. The places that went down after the quake were restored (for the most part) and people didn't notice much downtime, which is wonderful to hear given the need to communicate in crisis situations. If Japan's Internet can survive a quake like that, we should probably build our cables, fiber optics, and interwebs exactly like theirs. [Renesys via All Things D]