Nextels just don't work when TSHTF - heck, on bad regular days, they don't work. ASK your local Red Cross or Salvation Armay disaster manager. They were all ready to say "Bye" to hams at one point, then they figured out how poorly the Nextels really do (or any cell phone in REALLY bad spots)

As for FRS - the claim "up to 2 miles" - in real life, figure up to 1 mile, and in the city, a heck of a lot less. Even if there was a nextel with FRS, could you accept a range of < 1 mile, and a freq band with what, 12 channels?

Best bets?
1)CB - yeah, CB
2)GMRS - sort of like "super frs" but requires a license
3)convince the person/people you need to talk to to take the ham radio test. The "Tech" exam is REALLY REALLY easy