Hey, I am having the exact same problem, my ls -l /dev/by-* looks like:
lrwxrwxrwx 1 root root 13 2010-12-27 13:31 usb-Arduino__www.arduino.cc__Arduino_Uno_6493832333135110E051-if00 -> ../../ttyACM0
lrwxrwxrwx 1 root root 13 2010-12-27 13:31 pci-0000:00:1a.0-usb-0:1.3:1.0 -> ../../ttyACM0
I am on Ubuntu 10.10 64-bit, and I've installed the latest version of the RXTX library in the repository, 2.2pre2-1.
I downloaded the Arduino 22 linux 32-bit ide
I then replaced RXTXcomm.jar and librxtxSerial.so files in the lib directory with symlinks that point to the library files I installed using the repository.
Any help, I just got my Uno for christmas and would love to use it