New high-speed data plans, which began rolling out this spring from the major wireless providers, turn your cellphone into a modem, enabling you to get e-mail or surf the Web from anywhere at speeds of about 40Kbps. You can either connect via a laptop, or use your cellphone’s color display. Picking the provider that’s right for you depends on what you want to do. The more data-intensive your activities, the higher-speed network you’ll want. If you want to know the instant you get a message, look for a service with an always-on connection. Check here for a chart of providers.