The best replacement for hi5 is facebook.

The best alternatives to hi5 are rated as following:
★★★★★  facebook
★★  myspace
★  orkut
★  friendster
★  tagged
  high 5
  my space

Your alternative for hi5 is not listed? Suggest!
Speaking about hi5, one probably shouldn't forget about tagged.

Other search terms related to hi5 and their ratings are:
★★★★★ tagged
You have in mind a companion for hi5 and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of hi5 in all years. Click on graph for more.
hi5
facebook
myspace