Don't worry, it's not as bad as you think: But with the flooding of out-of-towners, limited reception areas, and an overflow Internet activity (the inauguration is going to have more bloggers than the DNC, Macworld, and a Nerve.com meetup combined), the National Guard swarming in to D.C. today and tomorrow should be the least of your worries. Let's figure out how to get cell service first.

The main issue is the Obama crowd, estimated at 2 million, mostly young people all trying to take pictures and send them at once. Those high rez grabs wouldn't be a problem at your average Fleet Foxes concert, but the sheer number of people trying to engage their smartphones all at once could cause a cellular blackout.

“If some of these estimates come true, people should anticipate delays with regards to sending text messages or making phone calls or getting onto the Internet,” said Joe Farren, spokesman for the Cellular Telecommunications and Internet Association, an industry trade group. It has asked people to send texts rather than make phone calls (text uses less bandwidth than speech) and to send photos only after the event.

“We can only bend the laws of physics so much,” Mr. Farren said.