USB drives have been born again, thanks to a new technology platform called U3, created by storage-product makers SanDisk and M-Systems (which have recently merged).

U3 technology allows next-generation flash drives to be used to run software such as Web browsers, e-mail clients, voice-over-IP (VoIP) phone services, and more. SanDisk of Milpitas, California, sent me two units for review; both are recommended in particular for those on the road, who will find that they can do everything on a business-center computer or airport kiosk that they could on a laptop, without leaving any traces of their work behind.

The 4 GB Cruzer Micro and the 2 GB Cruzer Titanium are alike in many respects. Both come preloaded with a host of useful software programs, including Skype for VoIP, antivirus protection through Avast, and CruzerSync, which synchronizes folders on the drive with the same folders on a PC or laptop. Both have a handy retractable USB plug.

The difference is on the outside. The Micro is small and made from lightweight plastic, while the Titanium has, as its name suggests, a rugged titanium exterior. When I asked SanDisk just how tough it was, they said it could withstand the weight of a car. So, I took a group of curious colleagues to the parking garage where we ran over the flash drive several times with a Honda Accord. The result? Hardly even a scratch on the drive’s surface. Plugged into my desktop, it worked perfectly.

Only software programs specifically designed to be U3 compatible will run on the drives. Most of these are available through the U3 and SanDisk Web sites, and include free programs such as the Firefox Web browser, OpenOffice.org (which includes word processing, spreadsheet, and other programs that are compatible with files in various Windows formats), and the Foxit Reader for PDF files. Also available are a variety of pay programs (many with free trials) such as Nullsoft Winamp (a media player), Anonymizer for anonymous Web surfing, and antispyware programs.

Pros. In addition to taking all necessary files on the road, now you can take the programs as well, meaning that any Windows computer, no matter what programs are installed, will always have everything you need to surf the Web or read or update a Windows document or spreadsheet.

Cons. Setting up an Internet connection for a Web browser requires some tinkering to match the connection settings of the computer that the flash drive is plugged into. And while the OpenOffice.org programs are compatible with Office programs, you won’t be able to keep files synched between the two.

Where to get one. The Micro is available through Internet retailers like Amazon for $124, and the Titanium goes for $83. Other size drives are available as well.