It's pretty easy to have more than one phone number for folks to call you on your cell phone, but it's not so easy to place calls from more than one number. Enter TalkPlus, now available for iPhone. This service gives you a second local number that can be used to place calls on your cell phone, courtesy of the TalkPlus service. TalkPlus' software masquerades your outgoing telephone number by transmitting your call using VoIP, and their data center does the rest.

iPhone users can access TalkPlus' suite of messaging and privacy features, which include a web-based visual voicemail and voicemail screening, which lets you listen while somebody is leaving you a message. Now that's just creepy cool. But the most useful feature is the second number, which needn't be in the same area code as your original cell phone number--so if you toggle between New York and London as a way of life, TalkPlus has you covered.