Rip Dev Blog - Currently working on Installer 4
Zibri's Blog - Ziphone creator
iPhone Dev Team Blog - Works on firmware unlocks, jailbreaking, etc
ModMyiFone Forum Site - Probably one of the best forums for iPhone/iTouch hacking
BigBoss' Blog - Works on many of the packages for Installer and Cydia
Jay Freeman's (Saurik's) Blog - Maker of Cydia
RupertGee's Blog - Great reviews and information about existing Cydia/Installer packages
If you have any links that you think would be nice to share, go to the Contact page on this site and send me a suggestion. I will not, however, give a link to Spicychicken's Customize website because Customize is a horrible, horrible application that ruins iPhones and iTouches.