MindInHand

Cool stuff at Mashup Camp or bookmarks stored in a blog. Big thanks to the organizers for
running such a nice space. Cool presentations and lots of self-organized events as well.

The folks from eventful , tourfilter and hypemachine.

Somebody mentioned HousingMaps a pretty slick mashup with google maps and craigslist housing listing - along with mapbuilder - a tool for making your own mashup.

Kapow is a excellent scraper. I guess dapper is too.

Gangstamaps brought more branding and interactivity to the mashup space.

original signal -blogs that follow web mashup
Programmable web - more mashup news.

AIM instant messenger has a great api. Its super easy to get robots up and running.

Firefox plugins worth checking out:
firebug - javascript debugger
tails - good for finding microformatted tags

Kevin Lawver gave some nice presentations on microformats

Massachusetts put its geographic data on the web here : http://www.mass.gov/mgis/
There is an open api to access it all.