For travelers using mobile smartphones (which can access the Internet), Globetrotter SOS, Ltd. (1 High St., Thatcham, Berkshire, RG19 3JG, UK; phone +44 845 003 9943, www.globetrottersos.com) has launched an emergency-response service which uses satellite-tracking technology and is available 24/7 anywhere in the world.

Services include “Inform You” (personal briefings on risks and current situations in over 400 countries); “Alert You” (notification while you travel of any situations...

The Transport Museum Dresden (Augustusburg 1, 01067 Dresden, Germany; phone +0351 86440, fax 8644-110, www.verkehrsmuseum-dresden.de [in German]) exhibits locomotives from 1924 to 1993 (such as the Saxon Muldenthal, built in 1861), cars, trams, motorbikes (the first gasoline-powered motorcycle, built in 1885), bicycles, hot-air balloons and airplanes.

It is located at the Johanneum, a Renaissance building (1586) where the Electors of Saxony kept their horses and carriages. Open 10-5...

In Liverpool, you can visit the childhood homes of John Lennon (Mendips, at 251 Menlove Ave.) and Sir Paul McCarthy (20 Forthlin Road) aboard the 14-passenger Beatles minibus. Memorabilia, photos and displays chronicle the composers’ early lives.

Both properties are conserved by and may be visited only on a tour booked through the National Trust (phone +44 [0] 151 427 7231, www.nationaltrust.org.uk). The 2½-hour tour costs £16 (near $25.50) per adult, £3 per child (5-16) or £7.50 for...