Briefly - Hopper is something new in the travel / local space. In their own words:
What if you could plan an amazing trip based on a vague idea — like “spring surfing in California” or “Mediterranean cruise”? What if logistical information popped up right when you needed it, so you wouldn't have to spend hours on research? This is our vision: to make planning a trip an effortless extension of discovering and exploring new places.
We spent several years experimenting with different tools, technology and algorithms to collect, organize and manage massive amounts of travel data. The result is a new kind of trip planning engine, powered by the world's largest structured database of travel information.
I've not remotely explored the site, but I see it as part of a trend which involves rich exploration experiences including plenty of imagery, the social aspect of local and specifically travel combined with smarts involving itinerary planning and travel booking. There are some similarities with the recently acquired RouteSet demo from PerceptLabs and also with the geo-microblog site Findery.
Visually, the exploration of a place on Hopper looks like this:
Which is to say - visually very rich with images provided (I assume) by the community. This wave of modern location products makes one ask the question - how important is the map for (engagement) in local search?
Right now, the site has some issues. As a signed in user I'm told to browse others' experiences and 'save' what I find interesting. Howerver, there is no mention of a 'save' action on any of the posts on the site. Consequently, it is a little hard right now to give a write up of how the site works. I do note posts have a reference to a source. Does hopper crawl these sources? or do the users cross post?
Update: regarding saving - a search on google for 'site:hopper.com save -near' surfaces pages which contain the word save, like this one: http://www.hopper.com/list/cities/-378 . However, the page itself according to Chrome has no instance of the string 'save' on it. Looking at the source for the page shows that there is actually a save button and other mechanisms in place. Not sure what is amiss here. Testing on IE also fails to surface any visible save functionality.
Update: I figured out the save mechanism. There is a star on each entity. Hitting the star *saves* the entity. This is a pretty poor design. Stars are generally used in interfaces associated with the term 'favourite'. Telling users they need to 'save' entities, then using a different metaphor for this action will, if I am any sort of average user, result in a lot of lost opportunity for engaging users.