One of my favourite web writers ever, Maciej Ceglowski, announces “an experimental set of Flash and JavaScripts add-ons to the Google Maps API” that allows for the presentation of very large datasets — the Million Marker Map:

One challenge we’ve faced is finding a way to display the 27,000 restaurants in New York without writing our own mapping engine from scratch. Current JavaScript maps from Google or Yahoo become noticeably pokey with just a few hundred markers on them, and effectively unusable once the number exceeds a thousand. The solution we’ve come up with is a kind of forced marriage between Flash 9 and the Google maps API that we’re releasing today as a standalone component called the Million Marker Map.

Maciej says it’s a buggy demo at the moment, but the component supports, in addition to million-marker-sized datasets, vector overlays.