Disassembling a $529 smartphone isn't for the faint of heart, so if you're going to try and tackle a project like this, you might as well know what you're up against. That's where DIY repair site iFixit.com comes in. You can think of iFixit as a community repair manual for all things tech, and one of the neater articles outlines how to take apart a Nexus One from start to finish.
Tearing into Google's smartphone you'll find a 1GHz Snapdragon processor, various logic boards, the touchscreen controller, GSM power amplifier, TI integrated Power Management IC, RF transreceiver, Bluetooth chip, LED flash, and all sorts of other tech goodies.
So why exactly would you want to take apart a Nexus One? Curiosity, out-of-warranty repair, and an obsession with taking things apart just for the sake of doing it are three quick reasons that come to mind. If you fall into any of those categories, check out the complete worklog (with pics aplenty) right here.