I have been inspired by Cal Evans' mashup experiment, which he did a presentation on at the Dutch PHP Conference last month. Also, I was annoyed with having to consult many different resources when I plan a business trip. So I began building frekfly, my own little mashup.
The post mentions two versions of the mashup - an initial version that pulled the services together and a second version that added in a web service for hotel information. This current version can be found at frekfly.com