Very good point about the single textbox limitation. I've been working a lot in this space, and I think there needs to be a protocol implemented beyond OpenSea

Very good point about the single textbox limitation. I've been working a lot in this space, and I think there needs to be a protocol implemented beyond OpenSearch, which is essentially limited to 1 text box, with some nice additions (i.e. you can specify a query suggestion URL as well). There should be some sort of superset to OpenSearch. I'm suggesting an AbstractForm protocol which would allow websites to export their basic query functionality into an an XML document. Relevant providers (such as Ubiquity, and the thing I'm working on that will be launched soon), would be able to use this protocol to integrate the provider's AbstractForm in a convenient interface. With Kayak, for example, AbstractForm might specify a "from" field of type "city", a "to" field of type "city", and some other optional fields (date, round trip, etc). You could then have a service which implements this however it chooses... perhaps a program with loads of AbstractForm interfaces loaded, and when you start typing "kayak" it knows to show you "To" and "From" fields, etc. I really believe this type of thing would be a major boon to the internet.