Not sure this requires much of a preamble - see our news piece on ebookers' new mobile site.
Ebookers has designed the site to be incredibly simple, but that verges on obligatory when producing pages for mobile browsers.
That said, it would be interesting to know how it performs on various different handsets - whether it's simple enough to be user-friendly on my clunky N95 as well as a web-friendly iPhone.
So if anyone has road-tested it, drop a note in the comments section...
Homepage
Search pages
Results pages
Works fine on my Android phone :)