A Federal court just rejected a last-ditch effort by US cellular companies to stop the FCC from imposing number portability, which means come November 24th you'll be able to switch your carrier and bring your number with you:

In April, attorneys for Verizon Wireless and the Cellular Telecommunications and Internet Association, an industry group, told a three-judge panel of the U.S. Court of Appeals for the District of Columbia that the FCC (news - web sites) overstepped its authority by imposing the requirement. They said it will raise costs while doing little to increase competition. The court rejected that challenge, calling the FCC's action "permissible and reasonable." The court also said the cell phone companies waited too long to object to the rule. "It is obvious that any regulation that frees consumers from staying with carriers with whom they are dissatisfied affords them protection," the court said. "It was reasonable for the FCC to conclude that wireless consumers would switch carriers at even higher rates if they could keep their phone numbers."

Now the cellphone companies will have to compete with each other on price and service, rather than being able to lock customers down because it's a hassle to get a new number every time you switch.
Read [Via BoingBoing]