Here are links to portals that have useful information and features. Click around and see what works for you. Feel free to add others you know about.
-nice, "clean" search interface
-everything our portal should NOT be!
-example with clickable maps
-this one I find difficult, do not understand ...
-this has interesting links to different types of visualizations and their information sources
-not a portal, but an interesting example of a tag-cloud, produced with Tagxedo
-Has very basic but clear search options
-Once in the accommodation search function, any changes you make to the search are automatically updated (similar to the new Google search function that posts pages and links while you type your keywords--Search Preview).
-One we all know: useful information but honestly not the greatest format.
-An interesting way to present maps.
- A great example of interactive maps.