The latest initiative is KLM's Dreamcatcher, a mashup site that aggregates practical travel information about destinations KLM flies to.
This information, that is pulled through APIs from twelve of some top content and travel review sites, such as Frommer's, Wikipedia or Tripadvisor, and is presented in a very visual Pinterest-style format.
According to KLM suggestions are presented by order of popularity (I imagine it is popularity among the users of the source content sites).
You can then pick up your favourites and create your own map of things to do and to see that you can then donwload to your smartphone to use when you are in the city of destination.
My impression after trying out this tool is that this is the kind of tool that might work best on smaller cities or for people that are really short of time, for example on a business trip, but still want to explore a bit a new city they find themselves in.
However, I am not sure whether the level of curation would be enough for someone planning a proper leisure trip to a major capital such as London or Paris.
Another challenge this type of apps face is making sure travelers get to know and use it regularly, as there is very intense competition out there between all sorts of travel apps and guides...of course, KLM has a great platform for distribution on its website, but whether people end up using the app on their trips, with the brand exposure this represents, or whether this finally leads to more tickets being sold might be another matter...
Nevertheless, kudos to KLM for its continous effort in developing new tools and apps for all of us that like flying and traveling!