Geek Guide to Baltimore

Visitors in search of American history often head to Baltimore's more-famous neighbor, Washington, D.C. But Baltimore has a rich history in its own right -- especially when it comes to technology. Baltimore was the first U.S. city to set up gas lights, the first U.S. city to host a passenger railroad, and the first U.S. city to create a citywide information hotline. Dial 311 to get answers from the city; for advice from adventurous geeks, see below.

Secret: National Cryptologic Museum

Most people these days associate cryptology with computers. And yes, the U.S. National Security Agency, home of the National Cryptologic Museum, runs the world's largest supercomputer facility. But the museum shows another side of cryptology. There's an 18th-century cipher wheel, secret message-passing flags from the Civil War, and a replica of a shack that housed World War I radio interception equipment. There's even a display about the metered postal stamp, an unsuspected application of cryptology. Of course, there's also a display that chronicles the development of supercomputers -- which is about as close as you'll ever get to the NSA's high-security labs.

Steamy: The Baltimore & Ohio Railroad Museum

A dramatic domed station, built in 1829, holds the biggest collection of railroad artifacts in the country. Diesel engines, communication devices, model railroads, track signals, dining-car dinner plates: it's all here. There's so much stuff that some of it has to go outside. But inside or out, these train treasures have a fitting home. The B&O station is the oldest passenger station in the U.S., as well as the home of its first home-built steam locomotive. Relive some of the glory by riding a real train to the site where the B&O first broke ground.

Smiley: National Museum of Dentistry

Think a National Museum of Dentistry sounds more like a National Museum of Torture? Think again. Sure, this Smithsonian affiliate showcases vintage tooth-pulling devices, menacing dentist's chairs, and George Washington's lower denture. But it also gives tips that'll help you avoid George's dental fate. An exhibit on spit -- ptooie! -- explains how developments in genomics benefit your pearly whites, and animations go over proper brushing practices and the dangers of oral piercing. For dental advice in the comfort of your own home, check out the online exhibit

Working: Baltimore Museum of Industry

This museum celebrates Baltimore's tradition of innovation in fields both large and small. A full-scale print shop preserves an example of the world's first successful mechanical typesetting machine. A machinery tool shop, which features running belt-driven contraptions, houses an exhibit on the world's first submarine. And on the smaller end of the spectrum, a replica of a 1910 pharmacy honors the invention of Noxzema skin cream. The museum will delight people both large and small, because it mixes history with kid-friendly hands-on activities.

Wordy: Atomic Books

Tired of museum-hopping? Try shopping at one of the few independent bookstores in Baltimore. Alongside traditional books, Atomic Books stocks thousands of zines, or self-published magazines. Zines -- the granddaddies of blogs -- hold something for just about everyone, including geeks. Popular titles include 2600: The Hacker Quarterly and Blacklisted! 411: The Official Hackers Magazine. The bookstore also hosts plenty of readings, signings, and knitting circles, so check for upcoming events.