From this MetaFilter comment, a bunch o’links. This was an eye-opener for me about some of the great tools out there.
Github Git hosting and social network around open source projects,
Phabricator: Suite of tools for dealing with source code: code reviews, diff and audit tools, wiki, issue tracker, task tracker. If you did not already know about this, you must check it out. Trying to see if I can run my own instance on Dreamhost, or get it running on OSX.
arcanist (CLI for phabricator),
TextMate: really nice text / source code editor
the Twitter API, which I would now replace with the App.Net API (my app.net account)
Sprintly, Project management
Trello, Collaboration tool
Amazon Web Services, There’s a lot of products beyond cloud servers (EC2) and storage (S3)
Get Satisfaction, customer community builder
ZenDesk, customer support software
Stack Overflow, You’ve already used this, admit it!
Hacker News a reddit-style community supported by the tech startup incubator. High quality tech news and discussion. Can be too obsessed with the new hotness / startup dramas, but generally excellent at tracking technology and business issues.