Adrian Holovaty of Everyblock spoke about EveryBlock and lessons we can all learn about web mapping sites.  Essentially, EveryBlock is a news feed for your block.  EveryBlock pulls from various news and public sources and makes them searchable/mappable/deep linkable in a very localized area.  Very cool stuff.

Highlights:

"On the web, not of the web": Too many sites that have maps on them don't interact with the rest of the web.  Ask yourself this question: "Will my site work without maps?".  Make everything deep linkable...it matters.

"Move beyond points": Not many mashups use lines or polygons...too many are point focused.  If you're data applies to areas or "lines" use them...don't take the easy way out with points.

"Roll your own maps":  Sometimes Google Maps and VE aren't really what you need in your app...it's one size fits all mapping.  Why do we accept Google/Yahoo/VE as default maps?  You wouldn't use a Wordpress template for your corporate website would you?  Roll maps that enhance your data visualization, not Google's.  Take control of your maps.  EveryBlock is using MapNik and OpenLayers to roll their own stuff.