The best replacement for tripit is tripcase.

The best alternatives to tripit are rated as following:
★★★★★  tripcase
★★★★★  worldmate
★★★  tripit pro
★★★  kayak
★  tripdeck
★  awardwallet
★  pageonce
★  flightview
  tripadvisor
  tripomatic
  triptracker
  blackberry travel
  dopplr
  checkmytrip
  concur

Your alternative for tripit is not listed? Suggest!
Speaking about tripit, one probably shouldn't forget about flighttrack pro.

Other search terms related to tripit and their ratings are:
★★★★★ flighttrack pro
You have in mind a companion for tripit and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of tripit in all years. Click on graph for more.
tripit
tripcase
worldmate