I love the fact that more and more devices are sporting built-in Wi-Fi—the Sony PSP, smartphones, even Kodak’s EasyShare-One digital camera. The lone hitch: Wi-Fi is useless without a hotspot. Sure, thousands of spots are available, but few are free, and coverage is far from ubiquitous. What if you could marry the short-range power of Wi-Fi with the huge coverage areas of high-speed cellular services such as EV-DO to create a portable hotspot?

A: Tagging is the act of assigning your own keywords to things online-photos, blog entries, bookmarks-so that you can easily categorize, locate, and share them in the future. One of the best examples is del.icio.us, which lets you save Web bookmarks to a page on the site instead of to a file stashed away on your computer. This way, you can access them from anywhere and let other people see what sites you like.