The best replacement for sim is micro sim.

The best alternatives to sim are rated as following:
★★★★★  micro sim
★★★★★  usim
★★★  smu
★★★  cdma
★★★  mdis
★★  mini sim
★★  kaplan
★★  nano sim
★★  gsm
★★  unisim
★★  phone
★★  sim
★  phone contacts
★  aim
★  scan
★  sit
★  microsim
★  aim
★  psb
★  sem
★  32k sim
★  micro sd
★  64k sim
  ebo elder
  usim card
  christopher lee
  strategic intervention material
  regular sim
  sim card
  standard sim
  phone memory
  normal sim
  micro sim card

Your alternative for sim is not listed? Suggest!
Speaking about sim, one probably shouldn't forget about data.

Other search terms related to sim and their ratings are:

★★★★★ data
★★★★★ tablet
★★★ no pin lock to activate iphone
★★★ phone
★★★ tablet price
★★ 112
★★ free credit
★★ nextel phone
★★ gprs
★★ puk
camera mobiles
free internet
changing number
changing your number
verizon phone
You have in mind a companion for sim and it is not yet here? Propose!

Google Trends

Scale is based on the average worldwide traffic of sim in all years. Click on graph for more.
micro sim