- you seem to have some crazy js loading on the facebook auth page. In chrome/mac it resized my window to fill my screen length wise. I would recommend going with facebook's default auth popup. Then again maybe you are and their js was just acting goofy.
- the image resources on the autocomplete for your location suggestions do not load.
- the video explanation after you sign up could be more clear. Maybe have some steps to go through in order to "complete" my signup process like making my first recommendation and planning a trip.
- when I create a trip and select that "me myself and I" are going on the trip (ie. I am going alone) the trip shows that two people are going on the trip.
- A lot of the encouraged interaction on the site seems passive. I suspect people are going to be good about setting up their own trips but lazy about making recommendations for other people's trips. Whether it's gamification or something more you should find some way to encourage or even force people to interact.