I had trouble getting the Android toolchain working under Fedora 14 with my Nexus One. The Android documentation only gives the correct udev rules for Ubuntu, so I had to dig around to find something that worked.
My solution is to add the following into /etc/udev/rules.d/51-nexus-one.rules. You should not need anything besides this to get it working.
SUBSYSTEM=="usb", ATTRS{idProduct}=="4e12", ATTRS{idVendor}=="18d1", MODE="0666" SYMLINK+="android_adb"
After which you run udevadm control --reload-rules
, and plug in your phone. At this point, lsusb should display your Nexus in the listing.