The point 22 doesn't have any samples: A web based database/Excel hybrid. I think Wufoo (a YC company), if used for oneself, could be thought as something like this.
I keep coming back to this idea over and over. DabbleDB was sort of like this but it closed shop after a talent acquisition. Formstack.com (formerly hosted at formspring.com) had very cool table-building tools but it appears they pivoted to become yet another Wufoo/SurveyMonkey. JotForm is somewhere between Wufoo and a database. FormLogix is another form-builder. Hyperoffice.com and Zoho.com/creator sell themselves as MS Access alternatives. FileMaker.com is probably the closest thing to pg's request.
Nevertheless, I still feel there exists a sweet spot that nobody has managed to reach yet. But I don't know how I'd go about finding out if people would really pay for a good excel-db hybrid web-app or not, considering so many alternatives exist, many of them nearly free.