* http://www.snapengage.com (sales/support chats)
* http://www.zendesk.com (basic KB & support tickets)
* http://www.github.com & http://www.springloops.com (public & private repositories)
* http://www.geckoboard.com (dashboard of financial state of the company)
And I'm a power user of my own SaaS products:
* http://www.w3counter.com (realtime visitor analytics)
* http://www.w3roi.com (ad performance tracking)
* http://www.dialshield.com (automatically calls high fraud risk customers during the checkout process on my ecommerce sites)
http://Elance.com - Remote contractors. Hourly or job based
http://oDesk.com - Virtual Admins
http://Freshbooks.com - Automation of invoicing. My average days to pay are about 9. A bill I am very happy to pay each month. I use chronomate as the time tracking portion.
http://adroll.com - advertising retargetting
http://join.me - free screen sharing better than go-to-meeting
http://highrisehq.com - CRM
Services I use on my own projects: url2png (thumbnail generation of web pages), pusher (real-time data push of server stats to a web page), google analytics (visitor stats)
My own SAAS projects: mindcast (corkboard for mashing up 3rd-party saas windows and notes), shadowcatcher (screen capture and screenshot sharing utility)
zendesk (customer support),
github (private repo),
campfire (team communication),
google apps (email, docs),
odesk (extra hands),
highrise (potential-investor relations),
clicky (real time web analytics),
dropbox (file sharing),
wordy (proof-reading),
mygengo (translations),
new relic (monitor rails apps),
zerigo (dns),
sendgrid (sending mails),
hoptoad (app logging),
transloadit (image uploading, processing),
heroku (app hosting)
Edit: learned HN formattingGitHub, Pivotal tracker, Basecamp, Campfire, Campaign monitor, Send grid, NewRelic, Litmus
Good question, would love to see others chip in!
1) github 2) pivotal tracker 3) campfire 4) olark 5) cheddargetter (technically)