How do I mount my phone? I'm super puzzled because my phone used to just appear when I plugged it in. It doesn't anymore and The development options are definitely set to allow USB debugging. The phone is charging via USB but doesn't appear in lsusb:

[0 amanda@luna android-sdk-linux_86]$ lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 004: ID 17ef:4807 Lenovo UVC Camera
Bus 003 Device 012: ID 413c:1003 Dell Computer Corp. Keyboard Hub
Bus 003 Device 003: ID 08ff:2810 AuthenTec, Inc. AES2810
Bus 003 Device 013: ID 413c:2010 Dell Computer Corp. Keyboard
Bus 003 Device 014: ID 046d:c001 Logitech, Inc. N48/M-BB48 [FirstMouse Plus]


adb devices -l shows nothing.

Based on some instructions on the internet, I also went into my Wireless and Network settings and changed the USB connection settings to "Mass storage" -- they were set to "Ask on connection" though I definitely wasn't getting asked. I don't get any Click here to connect via USB alert either. 

I wouldn't be surprised if I clicked some "stop asking me" button at some point, but I don't see how to undo that.  What else should I be doing to mount my phone?
I asked the same question over on Ask Ubuntu and someone suggested it was a dodgy USB cable. I'm kind of speechless, but indeed, swapping the cable solved my problems. Now when I plug my phone in to a USB port, I get a little notice that the USB is connected. Onward.