Services I use for consulting assignments: basecamp (file sharing), harvest (time tracking), go-to-meeting (screen sharing), skype (phone calls), gmail (e-mails), hellofax (faxing paperwork that involve my signature)

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)