According to the July issue of Wired, Nomophbia stands for "no mobile" phobia -- the "anxiety produced by losing cell phone contact, for lack of coverage or power. Of course, there's a Wikipedia entry on nomophobia.
Please don't confuse this with nomatophobia, defined as "a fear of names or other words because of their meaning." Ironically for a fear of names, the condition is also known by a second name: onomatophobia. I might call that ohno-onomatophobia: the fear of forgetting which onoma-related phobia with which you're afflicted. (Onoma is the Greek word for name.)
Back to nomophobia, the Wikipedia article says that a survey commissioned by the UK Post Office -- if it's anything like its US counterpoint, doesn't it have something more relevant to study? Like improving delivery efficiencies? -- and found that "53 percent of mobile phone users in Britain tend to be anxious when they 'lose their mobile phone, run out of battery or credit, or have no network coverage.'"
Additionally, the study compared stress levels induced by the average case of nomophobia to be on-par with those of 'wedding day jitters' and trips to the dentists.
Imagine needing a survey to find out that people now must have their cell phones with them and hate being disconnected through low battery or poor coverage. Fear of poor coverage is a major selling value proposition in most ads for cell phone service: "We've got more bars" or "America's most reliable network." I just don't think you needed a survey to uncover yet another condition of 21st century life.
Meanwhile, I can only imagine the pre-wedding jitters one might if one's cell phone didn't work.
Spoiler Alert: Actually something like that happened in the "Sex and the City" movie. If only Carrie had realized she suffered from nomophobia! Could have spared us all a long, dull part of the movie.