A canvas-based horizontal slider that would almost sway me from thinking thumbs up, thumbs down is the best rating UI mechanism.

"Facebook's address auto-completion in the compose message form is one of the best examples such behavior. The interaction very closely mimics what you would expect to happen in the To field of email applications like Apple Mail and Outlook."

somewhat specific to the iPhone.

lost track of this somehow... but I use it all the time in web forms. makes a list of checkboxes into a scrollable combobox widget

Kinda of figure it was possible to hack around these limits with javascript. Read the known issues at the bottom though for a nasty side effect of using this hack.