The challenge, in the post-DOS/Win3 era, is to jigger either Registry entries or applications so they dont need installing—and to either put data only on the flash drive, or to clean up all traces from the borrowed system during a clean exit.
U3s approach is to include an additional controller on the drive. According to U3 CEO Kate Purmal, theres no price bump to U3-ize a drive, and a pre-installed read-only partition for the U3 Launchpad software takes up a mere 5MB—thats noise level on todays 500MB to 2GB under-$100 flash drives.
U3-enabled USB drives—drives that bear a U3/Smart logo—are available from U.S. vendors such as Kingston Technology, Memorex Products, PNY Technologies and SanDisk. According to Purmal, Gartner predicts that 70 percent of 150 million flash cards that will be sold in 2008 will be U3/Smart.
To date, over 130 business and productivity, Internet, backup and synch, security, entertainment, and other applications have been created, ported or otherwise certified for U3. These include freeware applications like Yahoo Widget Engine 3.1 and suites like Mozilla, Thunderbird and OpenOffice.org. Theres also plenty of feeware, like Gaviri Technologys PocketSearch, organizers and games.
And with more than 10,000 software developers working with U3s SDK (software development kit), the odds are good that more apps are on their way. And theres no added cost. Most U3/Smart drives will include some apps preloaded; the U3 Launchpad includes links to the U3 Software Central repository.
U3 is pretty easy to use. Allot about 15 minutes to get the hang of whats where, and then start downloading free or trial versions of apps in addition to whatever comes preloaded on the USB stick you buy.
Things to like about U3 are the reasonably fast startup and exit and a good range of apps. One of the cons is that you can only use U3 or portable apps on a U3 drive.
U3 isnt the only apps-on-a-stick game in town, although the other approaches also have their pros and cons. Ceedos 2MB download ($29.95 after a free thirty-day trial) lets you use Ceedo-approved or portable apps. Ceedo takes longer than U3 to crank up, but seems to offers a little more access to your current programs, and you can use any USB stick (space permitting).
Mojopac, if I understand correctly, lets you install your current Windows apps, and run them, with your settings, in a secure session. One problem Ive encountered so far is that Mojopac has seriously gronked Windows Explorer, grrr—a dealbreaker, as far as Im concerned.
The safest and simplest way is to use portable applications—applications that dont need Registry entries, and dont leave data behind—like the trusty DOS apps of yore. PortableApps.com lists lots of these, including Firefox, along with e-mail, IM (instant messaging), media players and other apps like Putty and PuttyFTP. This isnt the same as a full-session environment, but theres less to go wrong.
Or, of course, if you can do a reboot from USB, you can do a Linux stick, or even Linux and a VMware virtual machine of your Windows system.
Two general caveats: 1) Use a password, and/or file encryption, if you are dealing with private or business data. 2) Be sure to use the included "Eject" utility, to make sure the mobile apps are finished cleaning up after themselves, in terms of removing any files or other traces from the computer, before disconnecting the USB drive.