For some time, Garmin USB devices are only available to root users of Ubuntu.  Here's a simple recipe for making your Garmin device available to all users.

You need to create a UDEV rule that specifies your device:

Create a new file for the rule,  you will need to use SUDO to save the file.  I use Sublime editor, so I use SUBL as the editor name:

• sudo subl /etc/udev/rules.d/51-garmin.rules

Just add this line to the file you created:

• ATTRS{idVendor}=="091e", ATTRS{idProduct}=="0003", MODE="666"

Now you should be able to send and receive data as a regular Ubuntu user.  

My favorite apps for accessing my Garmin 60CSX are:

• Viking
  https://launchpad.net/~rw-norris/+archive/viking
  This is a map visualization program that can read in various files and sources, and export out various files.  You can send data directly to your Garmin device from Viking.
• Gebabbel
  Via Ubuntu Software Center
  Released in 2007, and never updated, it is still the defacto front-end for the Gpsbabel command line program.  Uploads downloads, and converts from multiple files and sources.